C2.

Understand the structure of the atom KEYWORDS: Atom, proton, neutron,
Atomic structure Understand the structure of the atom ALL – State that atoms are made up of protons, neutrons and electrons MOST – Describe atoms in terms of mass and atomic number SOME – Perform calculations involving mass and atomic number Starter Find the definitions of the keywords below KEYWORDS: Atom, proton, neutron, electron

What is an atom? All matter is made up of atoms
LO: understand the structure of an atom What is an atom? All matter is made up of atoms However, an atoms is NOT the smallest unit of matter like you might have been previously taught Atoms of themselves made of smaller particles

The different parts of the atom
LO: understand the structure of an atom The different parts of the atom The middle part of the atom is called the nucleus Where have you come across this term before?

LO: understand the structure of an atom
What are atoms made of? Protons – Positively charged particles found inside the nucleus Neutrons – Neutral particles found inside the nucleus Electrons – Negatively charged particles that orbit the nucleus

What are atoms made of? http://www.youtube.com/watch?v=C7sshJHpCJo
LO: understand the structure of an atom What are atoms made of?

Task Draw an atom that has 5 protons, 5 neutrons and 5 electrons
LO: understand the structure of an atom Task Draw an atom that has 5 protons, 5 neutrons and 5 electrons Coomplete the paragraph below: Atoms were once thought to be the _________ unit of matter. However, we now know that the atom is made up of smaller __________. The ___________ of an atom is made up of protons and ___________. Protons have a ___________ charge and neutrons do not have a charge. Electrons ___________ the nucleus and have a ____________ charge. The number of protons and electrons in a neutral atom is the ________. Orbit, smallest, nucleus, neutrons, negative, particles, positive

Protons, neutrons and electrons
LO: understand the structure of an atom Protons, neutrons and electrons Particle Relative charge Relative mass Proton +1 1 Neutron Electron -1 1/2000 Where is the majority of the mass of the atom?

Relative sizes

Atomic and Mass number Atomic number: This is the number of protons inside the nucleus of an atom WARNING: Even though the number of protons and electrons in a neutral atom are the same, make sure you say the correct definitions if you are asked in an exam! Mass number: This is the number of protons + neutrons in the nucleus of an atom

Which is which? Atomic and Mass number
LO: understand the structure of an atom Atomic and Mass number Atomic number: This is the number of protons inside the nucleus of an atom Mass number: This is the number of protons + neutrons in the nucleus of an atom Which is which?

Example 1 Calculate the following quantities for the element below
LO: understand the structure of an atom Example 1 Calculate the following quantities for the element below Atomic number Mass number Number of protons Number of electrons Number of neutrons

Whiteboard example 1 Calculate the following quantities for the element below Atomic number Mass number Number of protons

Whiteboard example 2 Calculate the following quantities for the element below Atomic number Mass number Number of neutrons

Task Use your periodic table to find the following quantities for: nitrogen, oxygen, iron, platinum, gold, lead, mercury, potassium, calcium, phosphorus, argon, xenon Atomic number Mass number Number of protons Number of electrons Number of neutrons

State the three particles that make up the atoms
KNOWLEDGE CHECK C State the three particles that make up the atoms Start Timer 10 Minutes 10 What do the terms “atomic number” and “mass number” mean? Which of the numbers is bigger? 8 B 6 4 Explain what particles make up the majority of the mass of an atom and where they are found A 2

True or false? Copy the true sentences and change the false sentences to make them true: Atoms are the smallest unit of matter Atoms are made up of three fundamental particle: protons, neutrons and smurfs Protons are positively charged, neutrons are negatively charged and electrons are neutral The number of protons and electrons in a neutral atom is the same The atomic number is the number of protons in the nucleus of an atom

Electron arrangement Understand how electrons in an atom are arranged
Starter True or false? Understand how electrons in an atom are arranged ALL – State that electrons orbit an atom MOST – Draw electron arrangements for atoms SOME – Relate the number of outer electrons to reactivity KEYWORDS electrons, electron shells

Consider Calcium. Calcium has an atomic number of 20
LO: understand how electrons in an atoms are arranged Electron shells Consider Calcium. Calcium has an atomic number of 20 How many electrons does it have? All of calcium’s 20 electrons can NOT fit in one orbit. Therefore, there must be multiple orbits for electrons to occupy

Atoms have 4 shells where electrons can live
LO: understand how electrons in an atoms are arranged Shell break down Atoms have 4 shells where electrons can live Shell 1 – 2 electrons Shell 2 – 8 electrons Shell 3 – 8 electrons Shell 4 – Whatever is left!

Example 1 Draw the electron arrangement for sodium
LO: understand how electrons in an atoms are arranged Example 1 Draw the electron arrangement for sodium

Example 2 Draw the electron arrangement for oxygen
LO: understand how electrons in an atoms are arranged Example 2 Draw the electron arrangement for oxygen

LO: understand how electrons in an atoms are arranged
Whiteboard example 1 Draw the electron arrangement for potassium. It has an atomic number of 12

Whiteboard example 2 Draw the electron arrangement for hydrogen. It has an atomic number of 1

Task Complete the worksheet on drawing electron arrangements for atoms. Make sure you use crosses to represent the electrons and you remember how many electrons can go in each shell Stick the sheet in when you are done

Happy atoms Atoms are happiest when they have a full outer shell
LO: understand how electrons in an atoms are arranged Happy atoms Atoms are happiest when they have a full outer shell Atoms can get a full outer shell by stealing, sharing or losing their electrons. When this happens, you get a chemical reaction

Happy atoms Elements that have 7 electrons in their outer shell or 1 electron in their outer shell are usually very reactive. Why do you think that is?

KNOWLEDGE CHECK C B A State how many electrons can go into each shell
Start Timer 10 Minutes 10 8 Draw the electron arrangement for Nitrogen B 6 4 Explain why Lithium and sodium are extremely reactive element (they are both group 1 elements) A 2

Understand why chemical reactions occur KEYWORDS ionic, covalent,
Chemical bonding Starter Bingo Understand why chemical reactions occur ALL – State why elements react together MOST – Define ionic and covalent bonding SOME – Explain why group1 and group7 elements are very reactive KEYWORDS ionic, covalent, Electron shell

proton atom +1 neutron nucleus -1 electron 2 ATOMIC MASS 8 NUMBER
BINGO proton atom +1 neutron nucleus -1 electron 2 ATOMIC NUMBER MASS NUMBER 8

Practical – Chemical reactions
LO: understand why chemical reactions occur Practical – Chemical reactions Aim: To compare the properties of the reactants and products of chemical reactions: Method: Light the magnesium using the Bunsen burner Make sure you don’t look directly at the magnesium when it is burning Once the magnesium has completely reacted, see if you can get products to burn

LO: understand why chemical reactions occur
Conclusion What can you say about the reactivity of the magnesium compared to the magnesium oxide (the products). Why do you think that it?

Chemical reactions occur because an element is trying to get a full outer shell Once a reaction has occurred, the products are not likely to react again as they have already got their full outer shells

Chemical bonds When a reaction has occurred, we say that a chemical bond has been formed between the two elements to form the compound There are two types of chemical bond: Ionic bond: Formed when atoms join together as a result of gaining or losing electrons Covalent bond: Formed when atoms join together as a result of sharing electrons

KNOWLEDGE CHECK C Describe why elements react together to form compounds Start Timer 10 Minutes 10 8 Explain what the terms “ionic bond” and “covalent bond” mean B 6 4 Argon is a noble gas and in group8 of the periodic table. Explain why this element is very unreactive A 2

KEYWORDS ionic, electrons, Sodium chloride, group1, group7
Ionic bonding Starter Reaction of sodium and chlorine Define ionic bonding ALL – State the definition for ionic bonding and ions MOST – Describe elements that form ionic bonds SOME – Draw diagrams to represent ionic bonds KEYWORDS ionic, electrons, Sodium chloride, group1, group7

They are USUALLY formed between metals and non-metals
LO: define ionic bonding Recap What is ionic bonding? Ionic bond: Formed when atoms join together as a result of gaining or losing electrons They are USUALLY formed between metals and non-metals

LO: define ionic bonding
Likely culprits What elements on the periodic table are most likely to gain or lose electrons? Elements in group 1 (The alkali metals) react with non-metals to form ionic compounds Elements in group 7 (The halogens) react with metals to form ionic compounds

What happens? Sodium has an atomic number of 11. Chlorine has an atomic number of 17. What happens when they react to form an ionic compound? The molecules in an ionic bond are called ‘ions’. Ions are atoms that carry either +ve or –ve charges

Example 2 Magnesium has an atomic number of 12 and Oxygen has an atomic number of 8. Draw dot and cross diagrams to show how the elements bond together and the ions that the elements Mg and O make

Task Draw dot and cross diagrams to show how you would expect the following elements to form ions together. Show the ions formed for each bond: Lithium and Chlorine Calcium and Oxygen Aluminium and Chlorine Calcium and Chlorine Higher: 5) Aluminium and Oxygen

Future topics...

Exam practice Answer the questions on the topics we have learnt so far. Mark and correct the questions when you are done and stick them into your books

SPLAT Two people stand at the back of the room
There are two answers on the screen and only one is correct A question will be asked Whoever WALKS to the front the fastest and SPLAT’s the correct answer first is the winner!

proton electron

nucleus shells

Atomic number Mass number

No. of protons + neutrons

Periodic table Group 1

Noble gas Group 7

Covalent Bonding Define covalent bonding
Starter What is the question? Define covalent bonding ALL – State the definition of a covalent bond MOST – Describe covalent bonding in terms of electron transfer SOME – Independently Draw diagrams to represent covalent bonds KEYWORDS covalent, electrons, molecule, non-metals, share

LO: define covalent bonding
What is the question? Write the questions that go with the answers below: It is made up of protons and neutrons It was once thought to be the smallest piece of matter possible. We now know it is made up of smaller particles 8 An electron is transferred from one element to another It is the number of protons + neutrons that an atom has They are atoms that have either a positive or negative charges

Sharing electrons It is not always possible for an electron to be transferred from one atom to another When this happens, electrons are shared between atoms so that they can BOTH have a full other shell Covalent bonds are formed when electrons are shared between atoms

Covalent molecules It is not always possible for an electron to be transferred from one atom to another When this happens, electrons are shared between atoms so that they can BOTH have a full other shell Covalent bonds are formed when electrons are shared between atoms

Examples Ionic compounds Sodium Chloride Magnesium fluoride
LO: define covalent bonding Examples Ionic compounds Sodium Chloride Magnesium fluoride Lithium oxide Potassium sulphide Covalent compounds Carbon dioxide Water Methane Ammonia

Example question 1 Show how two hydrogen atoms can join together to form a covalent bond

Example question 2 The chemical formula of methane is CH4. Draw dot and cross diagrams to show the covalent bonds that exist in methane.

Whiteboard example 1 Show how two fluorine atoms can join together to form a covalent bond

Whiteboard example 2 Carbon dioxide is a covalent molecule made up of one carbon atom and two oxygen atoms. Draw dot and cross diagrams to show the covalent structure of this compound

Important things to remember!
LO: define covalent bonding Important things to remember! ALWAYS draw one atoms as having dots and the rest of the atoms as having crosses Ions are NOT formed during covalent bonding. They are only formed during IONIC bonding! IONIC = TRANSFERRING COVALENT = SHARING

Task Draw dot and cross diagrams to show how you would expect the following elements to form covalent bonds Hydrogen Chloride (HCl) Water (H2O) Ammonia (NH3) Chlorine molecule (Cl2) Hydrogen fluoride (HF) Higher: Oxygen molecule (O2) Nitrogen molecule (N2)

Plenary Write a rap/rhyme about all you have learnt so far about ionic and covalent bonding. Include the following keywords in your rap: Ionic Covalent Share Transfer HCl Ammonia

Homework – Due next week
LO: define ionic bonding Homework – Due next week Answer the selected exam questions on B2 (Biology). You will have learnt this last year with Mrs Elliott and this homework will help keep what you have learnt fresh in your head

Define metallic bonding Free electron, electrostatic force
Starter Brain teaser Define metallic bonding ALL – State what is meant by a free electron MOST – Describe the structure and bonding of ions in a metal SOME – explain how free electrons lead to strong bonds between ions KEYWORDS metal, ions, Free electron, electrostatic force

Starter You are working in a factory that makes pills that weigh exactly 1g. The factory has 9 production lines. Your manager tells you that one of the production lines has a fault and is making pills that weigh 1.1g. Using an electronic scale JUST ONCE how could you find out which production line has the fault?

Metallic bonding Where do the free electrons come from?
LO: define metallic bonding Metallic bonding Metals are very special and do not form either ionic OR covalent bonds. They form metallic bonds Metals exist as positive ions surrounded by a ‘sea’ of free electrons Where do the free electrons come from?

Metallic bonding What are some Properties of metals?
LO: define metallic bonding Metallic bonding What are some Properties of metals? The negative electrons sandwiched between the positive ions lead to strong electrostatic forces in the metal. This means that most metals have VERY HIGH melting/boiling points. When a current is applied, the electrons carry the charge. This is why metals can conduct electricity

LO: define metallic bonding
Metals exist as ___________ ions surrounded by a ______ of free electrons. These electrons are from the outer shell of the metal and are said to be ____________. The strong ____________ forces between the ions and electrons leads to ________ melting/boiling points in metals Electrostatic, sea, positive, high, delocalised

Practical – Growing metals
LO: define metallic bonding Practical – Growing metals Aim: To understand how metals form Method: Pour a small amount of silver nitrate into a test tube Place a piece of copper wire into the solution Leave in a test tube rack and observe how the crystals of silver form What do you observe? Why do the silver crystals form in the first place? What do you notice about the shape of the crystals?

KNOWLEDGE CHECK C B A What is a free electron
Start Timer 10 Minutes 10 8 Describe how metal ions and free electrons are arranged in a metal B 6 4 A Explain why metals have extremely high melting/boiling points 2

IONIC COMPOUNDS SIMPLE COVALENT MOLECULES GIANT COVALENT SUBSTANCES GIANT METALLIC STRUCTURES

Ionic Compounds Understand the structure of ionic compounds
Starter Draw the dot and cross diagram for the ionic bonding in Magnesium chloride Understand the structure of ionic compounds ALL – State what is meant by a giant ionic lattice MOST – Describe properties of a giant ionic compound SOME – explain the properties of a giant ionic compound KEYWORDS ions, giant, conduct Lattice , positive, negative, aqueous

Giant Ionic Lattice Ionic compounds exist as a Giant Ionic Lattice.
LO: understand the structure of ionic compounds Giant Ionic Lattice Ionic compounds exist as a Giant Ionic Lattice. This means the following: Lots of ions group together to make a large structure They structure has a regular arrangement There are alternating positive and negative ions

Properties What effect do these Strong forces have?
LO: understand the structure of ionic compounds Properties There are strong electrostatic forces between the opposite charges in the lattice What effect do these Strong forces have? A large amount of energy is required to overcome these forces which leads to: High melting point High boiling

What do you notice about the shape of the sodium chloride crystals?

KNOWLEDGE CHECK C B A State what is meant by a giant ionic lattice
Start Timer 10 Minutes 10 8 B Draw the giant ionic lattice for Magnesium Chloride 6 4 A Explain why ionic compounds have a high melting/boiling point 2

Practical – Conductivity of GIC
LO: understand the structure of ionic compounds Practical – Conductivity of GIC Aim: To determine the conductivity of GICs dissolved in solution Method: Dissolve a small amount of each ionic compound in a beaker of water Place electrodes which are connected to an ammeter and battery into the solution Measure the current, if one is produced and record it in a table Repeat with a different ionic compound What do your observations tell you?

Simple Covalent Molecules
Understand the properties of simple covalent molecules ALL – State what is meant by a simple covalent molecules MOST – Describe the properties of a simple covalent molecule SOME – explain the properties of a simple covalent molecule KEYWORDS: covalent, intermolecular

Simple covalent molecules
LO: understand the structure of simple covalent molecules Simple covalent molecules All of these molecules are simple covalent molecules What state do these molecules exist in at room temperature? What does that tell you?

Simple covalent molecules
LO: understand the structure of simple covalent molecules Simple covalent molecules Simple covalent molecules have relatively low melting and boiling points They typically exist as liquids or gases at room temperature They have strong covalent bonds within the molecules, but only weak intermolecular forces between molecules

Demo – Conductivity of SCM
LO: understand the structure of simple covalent molecules Demo – Conductivity of SCM Aim: To determine the conductivity of simple covalent molecules Method: Place the electrodes which are connected to a light bulb and battery into ethanol Measure the current, if one is produced What does the result tell you?

ARTICULATE Work in pairs!
One person faces toward the screen and the other away A word relating to the topic will come up on the screen. Describe the word to your partner WITHOUT USING THE WORD! You won’t have long to describe so work fast! Swap around after each word!

lattice

covalent

compound

electron

Intermolecular force

proton

nucleus

Atomic number

Sodium chloride

mass number

Giant Covalent Structures
Understand the properties of giant covalent structures ALL – State what is meant by a giant covalent structure MOST – Describe the properties of a giant covalent structure SOME – explain the properties of a giant covalent structure KEYWORDS: giant covalent structure, diamond, graphite, silicon dioxide, fullerene

Giant covalent structures
LO: understand the structure of giant covalent structures Giant covalent structures Whereas most non-metals form covalent bonds that form molecules, some form large networks of covalent bonds These networks are called giant covalent structures

Giant covalent structures
LO: understand the structure of giant covalent structures Giant covalent structures Examples of giant covalent structures include: Diamond Silicon Dioxide Graphite What do you know about any of these molecules?

LO: understand the structure of giant covalent structures
Diamond Diamond is made up entirely of carbon atoms. It is made when carbon is put under extremely high pressure and temperature Diamond has a melting point of 3550°C and is the hardest naturally formed substance known.

Silicon Dioxide Used in the production of glass. Has a melting point of 1600°C.

What effect do these delocalised electrons have?
LO: understand the structure of giant covalent structures Graphite Each carbon atom forms three covalent bonds. The extra electron that is not used to make a bond exists as a free (delocalised) electrons. What effect do these delocalised electrons have? Just as in metals, the delocalised electrons can carry the charge when a current is applied.

My name is Thomas Edison
My name is Thomas Edison! I invented the first production light bulb that had a graphite filament and could burn for 40 hours. However, the design was very fragile!

Graphite Graphite exists as separate layers that can slide over each other. For this reason it is used in pencils Graphite has a melting point of 3600°C.

Fullerenes Besides graphite and diamond, carbon can also form another type of giant covalent structure. Fullerenes (named after the scientists that discovered them) are made by conjoined hexagonal carbon rings

Uses of Fullerenes Possible uses of Fullerenes in the future could be:
LO: understand the structure of giant covalent structures Uses of Fullerenes Possible uses of Fullerenes in the future could be: Drug delivery In lubricants As catalysts in reactions To make carbon nanotubes to reinforce structures

Practical – Modelling molecules
LO: understand the structure of giant covalent structures Practical – Modelling molecules Use the molymods to create models of: A giant ionic lattice 2 simple molecules Diamond Silicon dioxide Graphite A fullerene

Giant Metallic Structures
Understand the properties of giant metallic structures ALL – State what is meant by a giant metallic structure MOST – Describe the properties of a giant metallic structure SOME – explain the properties of a giant metallic structure KEYWORDS: giant metallic structure, Free electrons, delocalised, malleable

Giant metallic structures
LO: understand the structure of giant metallic structures Giant metallic structures The ions that make up a giant metallic structure are arranged in layers. The layers can slide over each other and allow the metal to be bent into shape The free electrons hold the structure together and also allow metals to conduct electricity

LO: understand the structure of giant metallic structures
Homework You will have a test next week on all the material we have covered so far. The test will be marked in class. Whatever mark you achieve in this first test will be on your module report. Your homework for next week is to revise for the upcoming test.

Understand the nature and benefits of alloys
Starter Discuss with the people on your pod what you think an alloy is and any alloys that you might know Understand the nature and benefits of alloys ALL – State what is meant by an alloy MOST – Describe how alloys are created and some examples of alloys SOME – explain the benefits of particular alloys KEYWORDS: alloy, metal, Shape memory material

Alloys Can you name any Commonly used alloys?
LO: Understand the nature and benefits of alloys Alloys An alloy is a mixture of two or more elements, where at least one of the elements is a metal. Many alloys are mixtures of two or more metals Alloying metals can create compounds that are: Stronger More flexible Have a higher melting point Less easily corroded Lighter Can you name any Commonly used alloys?

Alloys Commonly used alloys are: Steel - Carbon and Steel
LO: Understand the nature and benefits of alloys Alloys Commonly used alloys are: Steel - Carbon and Steel Stainless steel – Carbon, Steel and Nickel Brass – Copper and Zinc Solder – Lead and Tin White gold – Gold, Nickel and Palladium

Atoms of second element
LO: Understand the nature and benefits of alloys How alloys are formed Atoms of second element In a normal metal, the atoms are arranged in a regular structure. In an alloy, the atoms of the second element fit into the spaces between the metal atoms. Having atoms in these spaces makes it more difficult for the layers to slide over each other. This is why most alloys are stronger than the metal alone

LO: Understand the nature and benefits of alloys
QWC question Explain what an alloy is and how the atomic structure of an alloy can make it stronger. Research shape memory alloys and what they are used for. Give examples where appropriate. 5-6 marks criteria: Knowledge of accurate information appropriately contextualised Detailed understanding, supported by relevant evidence and examples Answer is coherent and in an organised, logical sequence, containing a wide range of appropriate or relevant specialist terms used accurately The answer shows almost faultless spelling, punctuation and grammar.

Polymers Understand the formation and use of polymers
Starter Draw a spider diagram for whatever you remember about polymers from C1 Understand the formation and use of polymers ALL – State what is meant by a polymer MOST – Describe different kinds of polymers and their uses SOME – explain the difference between thermosetting and thermosoftening polymers KEYWORDS: polymer, monomer, Chain, plastic, LD, HD

LO: Understand the formation and use of polymers
Recap Polymers

A polymer is a long chain molecule that is made up of lots of small molecules that have been chained together. The small molecules that have been linked together are called monomers.

The role of Alkenes Alkenes are the perfect molecules for creating polymers. They double bond on an alkene can be opened up, giving extra bonds to attach things to. When the double bonds on lots of alkenes are opened up, they can be chained together to form a polymer

This is known as a polymerisation reaction
LO: Understand the formation and use of polymers Drawing polymers Drawing how polymers are formed MUST be done in a specific way Ethene This is known as a polymerisation reaction What do you think the Polymer is called?

Example question Draw how propene can be used to make a polymer. Name the polymer formed.

Mini-plenary Write definitions for the following keywords: Monomer
LO: Understand the formation and use of polymers Mini-plenary Write definitions for the following keywords: Monomer Polymer Polymerisation Double bond Name the polymers formed from the following monomers: Ethene Propene Styrene Vinyl Chloride Ethene terepthalate Vinyl Acetate

Practical – Making polymers
LO: Understand the formation and use of polymers Practical – Making polymers Aim: To make slime! Method: Measure out a small amount of PVA glue into a polystyrene cup Add a few drops of your preferred food colouring into a cup and stir well with a stirring rod Measure out 10cm³ of Borax powder and add it to your cup Stir vigorously! You may need to add more borax at this point if the mixture is still too gloopy Take your slime out of your cup when it sticks to the stirring rod and mould it with your hands! Compare the texture, consistency and strength of the polymer that you have formed to the monomer that you had before!

Poly(ethene) Formed at very high pressures with trace amounts of oxygen. Polymer chains are branched, making them hard to pack together Formed at lower pressures and using a catalyst at 50°C. Polymer chains are straighter, allowing them to pack closer together

Heating polymers How polymer chains are arranged can have a major effect on how they are affected by heat. There are two kinds of polymers that you are required to know about: Thermosoftening Thermosetting

Thermosoftening polymers
LO: Understand the formation and use of polymers Thermosoftening polymers The polymer chains are all coiled together However, there are no cross bonds between the molecules! When the polymer is heated, the molecules unwind and can slide past each other The material is flexible when it is hot and can be shaped When it cools, it hardens Heating the polymer causes it to soften again e.g. Polythene

Thermosetting polymers
LO: Understand the formation and use of polymers Thermosetting polymers The polymer chains are all coiled together There are cross bonds between the molecules! When the polymer is heated, the chains are linked to each other and can’t slide past each other Once moulded, the plastic will not soften when heated and can’t be reshaped e.g. Vulcanised rubber used to make tyres.

Task Complete the exam questions on alloys and polymers. Stick the questions into your books when you are done

Plenary Add to the spider diagram that you started at the beginning of the lesson whatever you have learnt during the lesson on polymers!

Nanoscience Understand the potential benefits and risks of nanoscience
ALL – State what is meant by nanoscience MOST – Describe some uses of nanoscience SOME – explain potential benefits and risks of nanoscience KEYWORDS: nanoparticles, catalyst, nanotubes, tumour

LO: Understand the potential benefits and risks of nanoscience
Starter You will be watching a video on nanoscience. Whilst you are watching the video, answer the following questions in your books: What does ‘nano’ mean? What are some applications of nanoscience? What are some risks of nanoscience?

Nanoscience is the science of really tiny things!
LO: Understand the potential benefits and risks of nanoscience Nanoscience Nano is a prefix that means ‘one thousand millionth’. Therefore, one nanometre is m, or one billionth of a metre. Nanoscience is the science of really tiny things! Nanoparticles have an extremely large surface area/volume ratio. This gives them incredible properties that we are only JUST discovering.

Marketplace What’s the catch?
LO: Understand the potential benefits and risks of nanoscience Marketplace Start Timer You will be given an information sheet on an aspect of nanoscience. In your group you must create an information sheet summarising what you have been given. What’s the catch? You can only use a maximum of 10 words but as many pictures as you like. 10 Minutes 10 8 6 4 2

Go shopping! Decide who is the ‘stall holder’ in your group.
LO: Understand the potential benefits and risks of nanoscience Go shopping! Decide who is the ‘stall holder’ in your group. They will stay sat at your table. The remaining members of your group are ‘shoppers’, you must each go to another stall and gather information about the other aspects of nanoscience. Remember to make notes to feedback to your group members.

What have you learnt Answer the following questions in your books in as much detail as possible: How are nanoparticles used in cosmetics? Describe how gold nanoparticles are used to treat cancer and destroy tumours How might nanotubes be someday be used in computers? What are scientists in the US Army developing that uses nanomaterials? What are the possible risks of nanoparticles? Do you think more research should be done into their uses, or should research be limited because of the dangers?

Plenary Make a spider diagram about everything you have learnt about nanoparticles in today’s lesson.

Rate of reaction Understand what is meant by rate of reaction
ALL – State the definition of a rate of reaction MOST – describe reactions that occur slowly and quickly SOME – explain how rate of reaction is calculated Starter Make a list of chemical reactions that you see in every day life KEYWORDS: rate of reaction, product, reactant, time

EVERYDAY CHEMICAL REACTIONS

LO: Understand what is meant by rate of reaction
Reactions happen at different speeds. A firework relies on a chemical reaction that happens in milliseconds whereas rusting is a chemical reaction between a metal and oxygen which can take years to happen

LO: Understand what is meant by rate of reaction
The rate of a reaction is how quickly the reactants are turned into products

Amount of reactant used
LO: Understand what is meant by rate of reaction Rate of reaction Amount of reactant used Rate of Reaction _______________ = Time taken Amount of product made Rate of Reaction _______________ = Time taken

Practical – measuring rate of reaction
LO: Understand what is meant by rate of reaction Practical – measuring rate of reaction Aim: To measure the rate of reaction Method: Weigh out a small amount of marble chips Weigh out a small amount of hydrochloric acid Place both into a conical flask on a balance Record how the mass of the mixture changes every 30s for 4 minutes

LO: Understand what is meant by rate of reaction Practical – measuring rate of reaction Time (s) Mass of mixture (g) Mass of product (g)

LO: Understand what is meant by rate of reaction Practical – measuring rate of reaction A-A*: Draw a line of best fit for your results and use your graph to calculate the rate of reaction B: Draw a line graph of your results and use it to calculate the rate of reaction C: Use your results to calculate the maximum rate of reaction and the minimum rate of reaction

KNOWLEDGE CHECK C B A State what is meant by ‘rate of reaction’
Start Timer 10 Minutes 10 State two chemical reactions that occur in everyday life, one very quickly and one very slowly 8 B 6 4 Explain how to calculate the rate of reaction A 2

Starter Write the questions that go with the answers below:
LO: Understand what is meant by rate of reaction Starter Write the questions that go with the answers below: It is how quickly reactants are turned into products They are a type of plastic which can be moulded again and again by heating them up They are a type of plastic which, once cooled and formed, can not be moulded again It is a long chain molecule made by linking together lots of smaller molecules It is a small molecule that is linked together with lots of the same molecule to make a polymer chain

Changing the rate of reaction
Understand the factors that affect rate of reaction ALL – Describe collisions theory MOST – describe the factors that affect the rate of reaction SOME – explain how each factor affects the rate of reaction Starter What is the question? KEYWORDS: rate of reaction, concentration, Temperature, surface area, catalyst

The answer is in a process called collision theory
LO: Understand the factors that affect the rate of reaction Collision theory We have already learnt about what happens when molecules react together. But HOW do molecules react together in the first place? The answer is in a process called collision theory

LO: Understand the factors that affect the rate of reaction
Collision theory Imagine we have a mixture of two substances. The molecules in the two substances will be moving about and may randomly collide with each other If the molecules collide with a little bit of energy, they will just bounce off each other and carry on going

Collision theory If the molecules collide with ENOUGH ENERGY, they will join together. This means that a chemical reaction has just taken place! The minimum amount of energy that is required for a reaction to take place is called the activation energy

Task Draw a comic strip to show how reactions occur between molecules. Include the following words in your comic: Collision, reaction, activation energy Make sure you show what happens when two molecules don’t have enough energy to react as well!

SURFACE AREA CONCENTRATION TEMPERATURE CATALYST

Practical – Surface area
LO: Understand the factors that affect the rate of reaction Practical – Surface area Aim: To investigate the effect of surface area on the rate of reaction Method: Measure out 10g of large marble chips Measure out 20cm³ of HCL Add the two substances to a boiling tube Place a bung with tube attached over the boiling tube Record how long it takes for the reaction to stop Repeat with small marble chips and powdered marble

Practical – Surface area
LO: Understand the factors that affect the rate of reaction Practical – Surface area A-A*: Calculate the average time for the reaction for each of the substances and draw a bar chart of your results. Use this to make a conclusion for how surface area affects rate of reaction C-B: Calculate the average time for the reaction for each of the substances and use this to make a conclusion for how surface area affects rate of reaction

Effect of surface area The powdered marble has a MUCH LARGER surface area than the marble chips This means that there is a MUCH LARGER AREA for the molecules in the hydrochloric acid to collide with Collisions will be more frequent There is more chance for the collisions to have the minimum activation energy The rate of reaction will be greater with the powdered marble chips!

Practical – Concentration
LO: Understand the factors that affect the rate of reaction Practical – Concentration Aim: To investigate the effect of concentration on the rate of reaction Method: Measure out 25cm³ of sodium thiosulphate and place this into a conical flask Place the flask over a piece of paper with a large X draw on it Add 25cm³ of 0.1M HCl Gently swill the mixture Record how long before you can no longer see the X Repeat the experiment with 0.5M, 1.0M and 1.5M HCl

Practical – Concentration
LO: Understand the factors that affect the rate of reaction Practical – Concentration A-A*: Calculate the average time for the reaction for each of the concentrations and draw a line graph of your results. Use this to make a conclusion for how concentration affects rate of reaction C-B: Calculate the average time for the reaction for each of the substances and draw a bar chart of your results. Use this to make a conclusion for how concentration affects rate of reaction

Effect of concentration
Increasing the pressure of two gases will have the same effect for the same reasons! LO: Understand the factors that affect the rate of reaction Effect of concentration The higher concentration acid has MORE MOLECULES of HCL than the lower concentration acid. This means that there are MORE MOLECULES OF HCL that can collide with molecules of the sodium thiosulphate Collisions will be more frequent There is more chance for the collisions to have the minimum activation energy The rate of reaction will be greater with the higher concentration acid

Practical – Temperature
LO: Understand the factors that affect the rate of reaction Practical – Temperature Aim: To investigate the effect of temperature on the rate of reaction Method: Measure out 20cm³ of 0.5M HCL into a conical flask Add a small piece of magnesium ribbon Note the number of bubbles and how quickly they are produced Repeat the experiment, this time gently heating the hydrochloric acid using a Bunsen burner Note how the number and frequency of bubbles changes with the higher temperature

Practical – Temperature
LO: Understand the factors that affect the rate of reaction Practical – Temperature Make a conclusion for the effect of a catalyst on the rate of reaction. Use the observations from your experiment to justify your conclusion

Effect of Temperature The molecules in the acid will move faster when they are heated up This means that there are more molecules that have the minimum activation energy for a reaction Because the molecules are moving faster, collisions will be more frequent There are more collisions and more of them have the minimum activation energy The rate of reaction will be greater with the hotter acid

What is a catalyst? A catalyst is a substance that speeds up a rate of a reaction, but does not get used in the reaction. They are usually very expensive metals (platinum, gold etc.), but using them can significantly improve the rate of an industrial reaction.

Practical – Catalyst Aim: To investigate the effect of a catalyst on the rate of reaction Method: Measure out 25cm³ of hydrogen peroxide Add a small amount of manganese oxide Measure the amount of oxygen produced by the reaction

Effect of a catalyst The catalyst lowers the activation energy required for a reaction to occur This means that there are more collisions that have the minimum activation energy to react This increases the rate of reaction The catalyst does not get used in the reaction! It stays as it is and can be used over and over again!

Task Complete the exam questions on the factors that affect the rate of reaction. Stick them into your books when you are done

Plenary Create a spider diagram in your books of the factors that affect the rate of reaction and HOW they increase the rate of reaction

Exothermic and Endothermic Reactions
Understand exothermic and endothermic reactions ALL – Define the terms exothermic and endothermic MOST – Give examples of where these reactions occur SOME – Explain what happens during these reactions in terms of energy Starter Find the definitions of the terms exothermic and endothermic from the textbooks KEYWORDS: Exothermic, Endothermic, Energy, rate of reaction

LO: Understand exothermic and endothermic reactions
Exothermic reactions An exothermic reaction is one that transfers energy FROM the reacting chemicals TO the surroundings. More simply, it’s a reaction that gives off heat

Exothermic examples Burning fuels Neutralisation Respiration
LO: Understand exothermic and endothermic reactions Exothermic examples Burning fuels Neutralisation Respiration

Endothermic reactions
LO: Understand exothermic and endothermic reactions Endothermic reactions An endothermic reaction is one that TAKES IN energy from the surroundings. These reactions are a lot less common than exothermic reactions

Practical – Endothermic reaction
LO: Understand exothermic and endothermic reactions Practical – Endothermic reaction Aim: To investigate the temperature change during an endothermic reaction Method: Measure out 20cm³ of citric acid and place in a conical flask Measure the initial temperature of the acid Add three spatulas of sodium hydrogencarbonate and stir Measure the temperature every 30s for 4 minutes

Practical – Endothermic reaction
LO: Understand exothermic and endothermic reactions Practical – Endothermic reaction Draw a line graph of your results with the time on the x-axis and temperature on the y-axis Make a conclusion for how you know the reaction was an endothermic reaction. Use results from your experiment to back up your conclusion

KNOWLEDGE CHECK State what is meant by an exothermic and endothermic reaction Start Timer C 10 Minutes 10 8 Give two examples of exothermic reactions B 6 4 Explain how chemical hand warmers work A 2

LO: Understand exothermic and endothermic reactions
Task Complete the exam questions on exothermic and endothermic reactions

Reversible reactions Understand exothermic and endothermic reversible reactions ALL – Define the term ‘reversible’ MOST – Give an example of a reversible reactions SOME – Explain the direction in which reactions will be exo/endothermic Starter Write the definitions of exothermic and endothermic in your books KEYWORDS: Exothermic, Endothermic, Energy, rate of reaction, reversible

A + B ⇌ C + D Reversible reactions
LO: Understand exothermic and endothermic reversible reactions Reversible reactions In normal chemical reactions, it is very difficult to change your reactants back to your products e.g. it is very difficult to make your cooked food back into its raw form However, in reversible reactions this IS possible! Reversible reactions are represented in a particular way A + B ⇌ C + D

Exo/Endothermic reversible reactions
LO: Understand exothermic and endothermic reversible reactions Exo/Endothermic reversible reactions EXOTHERMIC A + B ⇌ C + D ENDOTHERMIC If a reversible reaction is exothermic in the forward direction, then it will be endothermic in the backwards direction. i.e. if it gives out energy when moving in one direction, it will require energy to go in the opposite direction!

Hydrated Copper Sulphate AnhydrousCopper Sulphate
LO: Understand exothermic and endothermic reversible reactions Copper sulphate Hydrated Copper Sulphate (blue) AnhydrousCopper Sulphate (white) ENDOTHERMIC ⇌ EXOTHERMIC + Water Changing hydrated copper sulphate into anhydrous copper sulphate, requires energy. The reaction in the opposite direction, however, gives out energy.

Acids and Bases Understand the reactions of acids and bases
Starter Draw and colour in the pH scale. Label where you would find strong/weak acids, strong/weak alkalis and neutral Understand the reactions of acids and bases ALL – State the ions that make a solution acidic or alkali MOST – State the salt made in reactions between acids and bases SOME – Explain what happens in a neutralisation reaction using ions KEYWORDS: Acid, Base, Neutralisation, Salt, Ions, pH Scale

The pH Scale The pH scale is a visual way of representing
LO: Understand the reactions of acids and bases The pH Scale The pH scale is a visual way of representing acidity and alkalinity pH 1-6 = Acid pH 7 = Neutral pH 8-14 = Alkaline

What makes a substance acid or Alkali?
LO: Understand the reactions of acids and bases What makes a substance acid or Alkali? Acidic solutions contain lots of H+ ions. Alkali solutions contain lots of OH- ions. It is these ions which react with chemicals and make acids/alkalis so dangerous

A base is the name given for ANY chemical that CAN neutralise an acid.
LO: Understand the reactions of acids and bases What is a base? A base is the name given for ANY chemical that CAN neutralise an acid. An alkali is a special type of base that can be dissolved in water to form a solution

LO: Understand the reactions of acids and bases
What is a base? Bases are usually metal oxides and metal hydroxides. Of these, hydroxides are usually soluble and can be used to make alkaline solutions.

Practical - Neutralisation
LO: Understand the reactions of acids and bases Practical - Neutralisation Aim: To work out which indigestion tablet is the best at neutralising an acid Method: Add 20cm³ of HCl to four boiling tubes Add universal indicator to each of the boiling tubes and record the initial pH of the acid Grind up an indigestion tablet and add it to one of the boiling tubes Record the pH of the new solution Clean out the mortar and pestle and repeat with a new indigestion tablet

Practical - Neutralisation
LO: Understand the reactions of acids and bases Practical - Neutralisation Make a bar graph of your results with the tablet on the x-axis and the change in pH it produced on the y-axis. Use your graph to make a conclusion for which tablet was the most effective. Write an evaluation for your experiment. Identify 3 problems with the method and suggest 3 improvements that would make your results more accurate/reliable.

Acid + Base  Salt + Water
LO: Understand the reactions of acids and bases Neutralisation Neutralisation reactions ALWAYS have the following form: Acid + Base  Salt + Water Be careful! Salt in this case does not mean the stuff you put on your chips! It is just a general name used to describe the product made when an acid reacts with something!

Neutralisation reactions
LO: Understand the reactions of acids and bases Neutralisation reactions Sodium Hydroxide (aq) Hydrochloric Acid (aq) + Potassium Oxide (s) Sulphuric Acid (aq) + Aluminium Oxide (s) Nitric Acid (aq) +

General rules

Task Write the word equations for the reactions between:
LO: Understand the reactions of acids and bases Task Write the word equations for the reactions between: Potassium oxide and nitric acid Sodium hydroxide and sulphuric acid Calcium oxide and hydrochloric acid Sulphuric acid and lithium oxide Nitric acid and beryllium oxide Magnesium hydroxide and hydrochloric acid

Neutralisation reactions
LO: Understand the reactions of acids and bases Neutralisation reactions Neutralisation reactions can also be considered in terms of the ions that were mentioned before. When an acid and a base are reacted together the H+ ions in the acid react with the OH- ions in the alkali. This makes water i.e. H+ + OH-  H2O

Plenary Make a spider diagram about everything we have learnt about Acid and Bases ACIDS AND BASES

Making Salts Understand how salts can be made using acids
ALL – State the methods that can be used to make salts MOST – Create chemical equations to show the salts that are formed in reactions SOME – Explain the advantages and disadvantages of using certain methods of creating salts KEYWORDS: Acid, Base, Metal, Alkali, Salt, reactivity, insoluble

Methods of creating salts
LO: Understand how salts can be made using acids Methods of creating salts Salts can be made using acids by reacting them with three different substances: Metals – will give you the salt you want, but some metals are too reactive and so salts can’t always be made this way Insoluble bases – You can keep on adding the base until it stops reacting, then filter off the excess Alkalis – You can use an indicator to measure when the acid has been neutralise How can you get the salt from the solution after it has been made?

Creating salts using metals
LO: Understand how salts can be made using acids Creating salts using metals Reacting metals with water/acids can create the salts that we require. However, some metals are very difficult to obtain and others are very reactive. This method, therefore, isn’t ideal.

Practical – Creating salts
LO: Understand how salts can be made using acids Practical – Creating salts Aim: To create magnesium chloride using magnesium oxide and hydrochloric acid Method: Pour 20cm³ of Hydrochloric acid into a beaker Add a spatula full of magnesium oxide and stir Wait for all of the magnesium oxide to dissolve and then add another spatula Repeat the process until no more magnesium oxide will dissolve Filter the solution into a conical flask to get rid of any excess magnesium oxide Heat the solution using a Bunsen burner to get rid of the water and leave magnesium chloride

LO: Understand how salts can be made using acids Practical – Creating salts Hazard Risk Precaution

LO: Understand how salts can be made using acids Practical – Creating salts Aim: To create magnesium chloride using magnesium oxide and hydrochloric acid Method: Pour 20cm³ of Hydrochloric acid into a beaker Add a spatula full of magnesium oxide and stir Wait for all of the magnesium oxide to dissolve and then add another spatula Repeat the process until no more magnesium oxide will dissolve Filter the solution into a conical flask to get rid of any excess magnesium oxide Heat the solution using a Bunsen burner to get rid of the water and leave magnesium chloride

Task Answer the exam questions on neutralisation and creating salts
LO: Understand how salts can be made using acids Task Answer the exam questions on neutralisation and creating salts

Summarise today’s topic in 5 sentences.
LO: Understand how salts can be made using acids 5, 5, 1 Summarise today’s topic in 5 sentences. Reduce to 5 words. Now to 1 word.

Electrolysis Understand what is meant by electrolysis
ALL – State the definition of electrolysis MOST – Describe what occurs during electrolysis and know how to form half equations SOME – Explain how electrolysis is used to purify copper KEYWORDS: electrolysis, anode, cathode, Electrolyte, half equation, redox, copper

LO: understand what is meant by electrolysis
What is electrolysis? Electrolysis literally means ‘splitting up using electricity’. In electrolysis, we use electricity to break down (decompose) a substance into simpler substances.

What is electrolysis? In electrolysis, the electrolyte (substance being broken down) is dissolved or melted into a molten state. This separates the substance into positive and negative ions. The ions travel to different electrodes, separating the substance into simpler substances

Notes on electrodes The electrodes are usually made out of unreactive (inert) substances. Substances such as graphite, which will not react with the substances made are a common choice

Task Copy the diagram of the electrolysis setup, labelling the different parts

Definitions Electrolyte – The substance that is being broken down
LO: understand what is meant by electrolysis Definitions Electrolyte – The substance that is being broken down Anode – The electrode that is connected to the positive terminal of the battery Cathode – The electrode that is connected to the negative terminal of the battery Anion – The negative ions that are attracted to the positive anode Cation – The positive ions that are attracted to the negative cathode

KNOWLEDGE CHECK C B A What is the definition of electrolysis?
Start Timer 10 Minutes 10 Explain what the terms electrolyte, anode, cathode, anion and cation mean 8 B 6 4 Explain why an inert substance is used for the electrodes A 2

Electrolysis in detail
LO: understand what is meant by electrolysis Electrolysis in detail Let’s consider the electrolysis of lead bromide. Lead bromide is an ionic compound and can be dissolved in water. The lead forms positive ions with a charge of +2 and the Bromine forms negative ions with a charge of -1. Pb 2+ Br - Pb 2+ Br - Pb 2+ Br -

LO: understand what is meant by electrolysis Electrolysis in detail When the electrolyte is connected to a battery, the lead ions act as the cations. They have a positive charge and are attracted to the negative cathode. The Bromine anions have a negative charge and are attracted to the positive anode. - + Br - Pb 2+ Pb 2+ Br - Br - Pb 2+

LO: understand what is meant by electrolysis Electrolysis in detail At the cathode, the Pb2+ ions gain electrons and lead will form on the electrode. At the anode, the Br- ions lose the extra electron that they have and form Bromine gas. The electrolyte has now been split into separate substances. - Lead deposits + Bromine gas

Task Use your knowledge of electrolysis to draw a comic strip to show how lead bromide can be split into lead and bromine. Pb 2+ Br - Pb 2+ Br - Pb 2+ Br -

Half equations We can represent what is happening at the electrodes using ‘half equations’. For example, from the previous example, the following reaction will be occurring at the anode: 2Br-  Br2 + 2e- Two Bromine ions lose an electron each to form Bromine gas, depositing the electrons on the positive anode.

Half equations We can represent what is happening at the electrodes using ‘half equations’. For example, from the previous example, the following reaction will be occurring at the cathode: Pb2+ + 2e-  Pb The lead ions gain electrons from the negative cathode and form lead deposits on the cathode.

Example 1 Write half equations for the anode and cathode for the electrolysis of Copper Chloride (CuCl2). (Hint: Metals always form positive ions and non-metals always form negative ions)

Example 2 Write half equations for the anode and cathode for the electrolysis of Potassium Bromide (KBr). (Hint: Metals always form positive ions and non-metals always form negative ions)

Task Write half equations at the anode and cathode for the electrolysis of the following substances: Calcium Chloride (CaCl2) Sodium Chloride (NaCl) Lithium Fluoride (LiF) Beryllium Bromide (BeBr2) Magnesium Oxide (MgO) Magnesium Chloride (MgCl2)

KNOWLEDGE CHECK C B A What is a half equation?
Start Timer 10 Minutes 10 Describe the process of electrolysis in terms of the ions present and what occurs at the electrodes 8 B 6 4 Construct the half equations for the electrolysis of Copper Bromide (CuBr2) A 2

Purifying Copper

Purifying Copper Besides separating substances, electrolysis can also be used to purify copper and to extract metals from their ores. Copper is an extremely useful and valuable metal. It has a low reactivity and very low resistance, making it ideal for use in electrical wires.

Task Read pages of the additional science textbook. Use the spread to answer the following questions: What impurities may be present in naturally found copper? Why is it important to remove these before the copper can be used for electrical wires? Describe how the purification of copper is conducted. Draw the set up of the electrolysis equipment Write half equations for the reactions that occur at the anode and cathode Explain what is done to the copper once it is purified.

Plenary Draw a spider diagram of everything you have learnt today about electrolysis ELECTROLYSIS

Extracting Aluminium Understand how Aluminium is extracted
Starter Write a definition for Electrolysis – You will have learnt this in last week’s lesson Understand how Aluminium is extracted ALL – State some uses of aluminium MOST – Describe the process for extracting Aluminium SOME – Explain why Aluminium is dissolved in Cryolite during electrolysis KEYWORDS: Bauxite, Cryolite, Electrolysis

LO: understand how Aluminium is extracted
Aluminium is a very versatile metal. It is light and does not corrode or rust easily, meaning it can be used to make everything from drink cans to aeroplane parts. However, it is very expensive to extract, mainly because of the amount of electricity that is used to extract it

Aluminium is usually found in an ore called Bauxite
LO: understand how Aluminium is extracted Extracting Aluminium Aluminium is usually found in an ore called Bauxite The Bauxite is purified to form Aluminium oxide. This is a white powder, from which Aluminium can be extracted.

Extracting Aluminium Aluminium oxide has a melting point of 2000°C! Melting this would be extremely expensive! Instead…. The Aluminium oxide is dissolved in molten Cryolite. The Cryolite has a melting point of about 1000°C, reducing the cost of extracting Aluminium (slightly…)

Extracting Aluminium The dissolved aluminium oxide can then be separated using Electrolysis. Graphite anodes and cathodes are used to conduct electricity through the molten electrolyte

Extracting Aluminium The Aluminium forms Al3+ ions in the solution. They are attracted to the negative cathode, where they form molten aluminium.

Extracting Aluminium At the positive anode, O2- ions form Oxygen. The oxygen reacts with the graphite (a type of carbon) to form carbon dioxide. The anode must therefore be regularly replaced.

Task Make a flow diagram of the process of extracting aluminium from its ore Bauxite. Make sure you are clear about each step in the process and why it is done.

Electrolysis ELECTROLYTE bauxite ACID COPPER cryolite NEGATIVE 2000°c
BINGO Electrolysis ELECTROLYTE bauxite ACID COPPER cryolite NEGATIVE 2000°c ALUMINIUM OXIDE anode ALKALI

Einstein Time THAT’S ALL FOR C2!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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