Putting Atoms Together

Putting Atoms Together
Chapter 7

Terminology Molecule –
Ex. Air = roughly 80% _______________ molecules, _____ oxygen molecules, and trace amounts of H2O and CO2 two or more atoms of the same or different elements that are chemically joined together in a unit. nitrogen 20%

Terminology notation that indicates the type and number of atoms in a pure substance Chemical Formula – - small numbers written ____________, in chemistry usually indicates a charge  – small number ___________, tells us how many atoms there are  Diatomic Elements – Superscript above/after Mg2+ Subscript below/after O2 = 2 oxygen atoms Elements that exist as molecular elements consisting of 2 atoms.

Diatomic Molecules mnemonics Have No Fear Of Ice Cold Beer. These seven elements occur naturally as molecules containing two atoms. “HONClBrIF”

How many valence electrons does it start off with?
What element is this? How many valence electrons does it start off with? How many does it end up with once it forms a bond? Flourine or Chlorine – they share one electron with on another, forming a stable (8 electron) valence shell

Molecular compounds Sharing is caring!

Terminology What do we call rxn’s that release energy/heat? What do we call rxn’s that require it? Molecular Compounds – Compound consisting of two or more different elements with neutral charges that are bonded together. Involves two _______________ (includes hydrogen) elements joining together and sharing their ________ electrons to fill their outer __________________ (shell). non-metal Exothermic - release energy in the form of heat, light, or sound and can occur spontaneously endothermic - absorb energy (temperature drop) in order to proceed, and cannot occur spontaneously. Work must be done in order to get these reactions to occur. valence energy level A simulation of the reaction: 2H2 + O2 ® 2H2O

hydrogen oxygen valence 2 8 sharing of electrons
Means electrons “LEAN” or migrate towards one molecule creating partial + and - charges Forces that hold atoms together Represent “potential” energy Illustration to the right shows two __________ molecules and a single _______ molecule. Hydrogen wants to have a full ________ shell (first shell can hold a max. of __) meanwhile the oxygen atom also wants to have a full valence shell (2nd shell can hold __). Therefore a ____________________ occurs. hydrogen oxygen valence 2 If oxygen only had 5 valence electrons (instead of 6), what would you expect its chemical formula to be? 8 sharing of electrons 2 H O  H2O

dependent on arrangement fixed amounts
A key aspect of molecular compounds is the fact they are ______________________ ____ ____________________. Only certain combinations in __________ _______________________ are found in nature. Ex. The above example highlights the fact that a change in ______________________________________ dramatically changes the ______________________________________________ dependent on arrangement fixed amounts O2 = Oxygen Gas, meanwhile O3 = Ozone configuration compound and how it affects us.

Bohr-Rutherford Lewis dot diagrams
These molecules can be drawn as __________________________________________ diagrams or as ____________________________________ with the shared pair of electrons represented by a _____, 2 pairs by a ______, or 3 sets of shared electrons by _____. The most that will ever be shared is 3. Bohr-Rutherford Lewis dot diagrams

Ionic Compounds

TERMINOLOGY Def. Ionic Compound: Involves a ___________ + a _____________ joining together, with the metal _____________ its ___________ _________ and the __________ taking them. Compound consisting of a positively charged (cation) and negatively charged (anion) ion. metal non-metal giving away valence electrons non-metal

Cation Anion Ions a particle that has a + or - charge
Def. Ion –_________________________________ 2 forms _________ = Positive _________ = Negative Cation Anion

Think about this silently (use your notes or textbook as a reference)
Why does the metal always give away its valence electrons and the non-metal always take them? Think about this silently (use your notes or textbook as a reference) ½ - easier for it to give up 1 or 2 than take 6 or 7 ¾ - smaller nuclear charge, weaker hold on valence electrons

ANSWER It is easier for a metal to give up 1 to 4 electrons than try to take enough to fill its valence shell. For non-metals, they generally only need 1 or 2 extra’s to fill their shells, so it is easier for them to take 2 than give up 6. Based on strength of nuclear charge

When an atom gains an electron, it becomes negatively charged (more electrons than protons ).
This is called an ________ In the same way that non-metal atoms can gain electrons, metal atoms can lose electrons. They become positively charged ________. anion cations

She’s unhappy and negative.
Ions Here is a simple way to remember which is the anion and which the cation: This is Ann Ion. This is a cat-ion. Two N’s in ANION for Negative A “T” in CATION for Positive She’s unhappy and negative. He’s a “plussy” cat!

Ionic Radius Cations are always smaller than the original atom.
The entire valence shell is removed during ionization. Conversely, anions are always larger than the original atom. Electrons are added to the valence shell to fill it up (stabilize it).

# of - Charge (Electron)
Sodium Atom, Na Sodium Ion, Na+ Chlorine Ion, Cl- Chlorine Atom, Cl # of + Charge (Protons) # of - Charge (Electron) Overall Ionic charge

Ions family Valence electron
Based on the way the periodic table is arranged, we already know/can predict the change of an ion based on the _____________ it belongs to. This is all based on its ____________ _________. family Valence electron

Draw Diagram from text (pg. 260) Copy the Bohr-Rutherford
Create a Lewis Dot Diagram

Draw a bohr-Rutherford diagram of sodium and chlorine combining to form sodium chloride.
Draw a lewis-dot structure of the same reaction

Sodium Ion, Na+ Chlorine Ion, Cl-

HW  Q 1-8 on page 261

Periodic Table Worksheet
REVIEW

Metals 1. _______ are located on the left side of the periodic table, with __________ located on the right side. They are separated by a “________” that touches the __________. 2. Horizontal rows are known as ________ and tell us the number of ______ _____ or ______ an element has. non-metals staircase metalloids periods Energy levels shells

Families columns 3. ________ or groups are vertical ________ on the periodic table and tell us how many valence _________ an element has. 4. ATOMS have the same number of Protons as they do ______ _______, so their charge is neutral, this information is detailed in the ______. electrons atomic number charge

charge valence electrons cations anions
5. IONS have a positive or negative _______ because they have given up their _______ _________ or taken valence electrons from an atom of another element in order to fill/empty their outer energy shell. 6. Positive ions are known as _______ (think the t looks like a +) while negative ions are called _______ (has two n’s for negative). valence electrons cations anions

Magnesium Atom Symbol = Period # = # of energy levels = Group # =
# of Valence Electrons = Member of the _____________ Family Draw a Bohr-Rutherford Diagram

Lithium Atom Symbol = Period # = # of energy levels = Group # =
# of Valence Electrons = Member of the _____________ Family Draw a Lewis-Dot Diagram

Argon Atom Symbol = Period # = # of energy levels = Group # =
# of Valence Electrons = Member of the _____________ Family Number of Neutrons = Draw a Bohr-Rutherford Diagram

Fluorine Atom Symbol = Period # = # of energy levels = Group # =
# of Valence Electrons = Member of the _____________ Family Number of Neutrons = Draw a Lewis Dot diagram

ION REVIEW Neon Helium phosphorus -3
a) An ION of fluorine is going to mimic (look like) an atom of ______. b) An ION of beryllium is going to mimic an atom of __________________. c) An ION of ____________ has to gain 3 electrons to mimic argon. Its ionic charge will be ____. Neon Helium phosphorus -3

Aluminum d) An ION of _________ has to give up 3 electrons in order to mimic an atom of neon. Its charge will be ___. e) An Ion of Oxygen has to ____ ___ electrons to mimic _____. Its ionic charge will be ___. +3 gain 2 neon -2

Calcium Atom Symbol = Atomic # = # of Protons = # of Electrons =
Ionic Charge = Atomic Mass (most common isotope) = Number of Neutrons = Draw a Bohr-Rutherford Diagram

Oxygen ION Symbol = Atomic # = # of Protons = # of Electrons =

chlorine ION Symbol = Atomic # = # of Protons = # of Electrons =

aluminum ION Symbol = Atomic # = # of Protons = # of Electrons =

Potassium ION Symbol = Atomic # = # of Protons = # of Electrons =

Questions from reading
How do atoms become more stable? When metals mix with another metal is it called an ________. When metals mix with non-metals it is called an __________ compound. What happens with the electrons in these compounds? When two non-metals mix it is called a ____________ compound. They form bonds with another atom in order to fill their valence shell Alloy Ionic They are given/taken Molecular They are shared

Pop Quiz What is an ion? What do we call positive & negative ions?
Describe ionic compounds /2 Describe molecular compounds /2 What type of compounds are the following… how many atoms in each? Water – H2O Methane – CH4 Table salt – sodium chloride – NaCl Potassium oxide – K2O What element does a Lithium ion mimic Draw a B-R diagram of a fluorine atom Draw a B-R diagram of a magnesium ion

Building Molecules

Think about it If you were told that an ionic compound formed between a single oxygen ion and a single metal ion, which family would you expect the metal to belong to and why? If you were told that an ionic compound formed between two magnesium ions and a single non-metal ion, what element would you expect to see bonded with the magnesium? If nitrogen gas was going to bond with an alkali metal, how many metal ions would you expect to see bonded?

Think about it If you were told that an ionic compound formed btw a single oxygen ion and a single metal ion, which family would you expect the metal to belong to and why? Alkaline earth metal, because their charges balance out… Oxygen is two away from being stable, so it wants 2 electrons… making it a negative 2 (-2) Family two elements have 2 valence electrons, so they want to give away 2 electrons, making them positive 2 (+2)

Think about it If you were told that an ionic compound formed between two magnesium ions and a single non-metal ion, what element would you expect to see bonded with the magnesium? Carbon! …or some other family 14 non-metal This is because each magnesium releases two electrons (-2 charge) for a total metal charge of negative 4 (-4) You need a non-metal looking for 4 electrons to balance it

Think about it If nitrogen gas was going to bond with an alkali metal, how many metal ions would you expect to see bonded? 3! …nitrogen is 3 away from being stable (full valence shell), so it wants to steal 3 electrons. Since alkali metals only have 1 valence electron, nitrogen must bond with 3 atoms of a alkali metal to fill its valence shell

Ionic compounds Names & Formulas

A ionic compound is made up of positive and negative ions (cation and anion) joined together by ionic bonds. A ionic bond result from a transfer of one or more electrons from one atom to another then joint together by electrostatic forces of attraction. Table salt For example, the arrangement of Na+ ions and Cl- ions in a crystal of sodium chloride. Each Na+ ion is surrounded by six neighboring Cl- ions, and each Cl- ion is surrounded by six neighboring Na+ ions.

REview metal Cation Anion
Compound consisting of a positively charged (cation) and negatively charged (anion) ion. Def. Involves a ___________ + a _____________ joining together, with the metal _____________ its ___________ _________ and the __________ taking them. Def. Ion –_________________________________  2 forms 1.) _________ = Positive 2.) _________ = Negative metal non-metal giving away valence electrons non-metal a particle that has a + or - charge Cation Anion

NAMING Ionic compounds are easily identified by the presence of a ___________ (first term). Any time you see a metal as the first term, you should automatically be thinking IONIC! Additionally, there is never a __________________ reference in the compound name (so no _________________). The nice thing about naming Ionic molecules is we __________ need to worry about numbers (subscripts). metal NUMERICAL PREFIXES DO NOT

2 Potassium Oxygen Potassium oxide Example  K2O
Determine how many elements (each capital letter represents a new element) are present in the compound (_______) and locate them on the periodic table. Is there a metal..? If so it must be a Ionic Compound. Identify which of the elements is the metal (it must go first). __________________ Identify the non-metal element (it goes 2nd). ____________________ Write the name of the metal, than the name of the non-metal (but change the ending of the non-metal to “IDE”). ___________ _____________ 2 Potassium Oxygen Potassium oxide

Try these… Li2O MgF2 NaCl K3N CaS Be3P2 LiBr Na2O Lithium oxide
CaS Be3P2 LiBr Na2O Lithium oxide Magnesium fluoride Sodium chloride Potassium nitride Calcium sulphide Berylium phosphide Lithium bromide Sodium oxide

WRITING chemical FORMULAS for Ionic Compounds
Since the electrons are ____________ and electrical _______ are present we need to reference the Periodic Table in order to determine how many of each element there is going to be. ____________________________! given/taken charges THE CHARGES MUST BALANCE

Step 1: Locate the elements in the Periodic Table- ensure one is a metal, and one is a non-metal. Write down their chemical symbol. Step 2: Determine the “charge” each element carries when its forms an ionic bond (remember: how far from STABLE) Step 3: Backcross the “charges“ to SUBSCRIPTS for each element +1 -2 Rb O Ex. Rubidium oxide +1 -2 Rb O Rb2O1 “charges it up” _____ _____  “backcross it down”

Compound Sodium chloride Magnesium nitride Calcium fluoride
Francium phosphide CHARGE FORMULA Na+1 Cl-1 Mg+2 N-3 Ca+2 F-1 Fr+1 P-3 Mg3N2 CaF2 Fr3P NaCl

Molecular Compounds Names and Formulas

Naming Molecular Compounds
Molecular compounds are made of 2 or more non-metals only. Non-metal atoms SHARE electrons with each other via COVALENT bonds. Def. This means there is no taking or giving of electrons, therefore there is no _________ IONS

These compounds are… Have a low melting point Do not conduct electricity Soft, do not form crystals Do not dissolve in water Solids, liquids, and gases

Tri Octa 1 2 3 4 5 6 7 8 easily identified
Molecular compounds are _____________________ by the use of PREFIXES. Anytime you notice a numerical prefix in a compound, you should automatically be thinking MOLECULAR and NON- METAL atoms. Mono Di Tetra Penta Hexa Hepta Tri Octa Nona – 9 Deca - 10 1 2 3 4 5 6 7 8

ide Example  H2O 2 2 1 ________ _______________ _____ ____________ Di
STEP 1: Determine how many elements (each capital letter represents a new element) are present in the compound (_______) and locate them on the periodic table. STEP 2: How many HYDROGEN (H) atoms are there? ________ STEP 3: How many OXYGEN (O) atoms are there? ________ STEP 4: Write the corresponding prefixes first (on the smaller lines), then the name of the element on the larger lines, remember to always change the ending of the second element to “IDE” just like we did yesterday with IONIC compounds. 2 2 1 ide ________ _______________ _____ ____________ Di hydrogen Mon oxygen

TRY THESE N2O BrI XeF4 ClO2 ICl2 S2Cl2 UF6 P2O5
ICl2 S2Cl2 UF6 P2O5 Dinitrogen monoxide Bromine monoiodide Xenon tetraflouride Chlorine dioxide Iodine dichloride Disulphur dichloride Uranium hexaflouride Diphosphorus pentaoxide REMEMBER: first term never includes mon(o)

WRITING chemical FORMULAS for Molecular Compounds
The ______________ in-front of the element tells you how many ______________ (units) of that element there are in the formula. These numbers are to be written as SUBSCRIPTS after the elements symbol. PREFIX atoms

N O STEP 1 – write the symbol for each element on the top lines
STEP 2 – write the corresponding prefix number as a subscript (below and after) each elements symbol Ex. Dinitrogen tetraoxide  ___ ___ N O 2 4

Diphosphorus pentasulphide
TRY THESE Notice that the first term sometimes lacks a prefix… what does this mean again? Nitrogen dioxide Dinitrogen monoxide Sulphur trioxide Diphosphorus pentasulphide NO2 N2O SO3 P2S5

Worksheet Work through all the sections
Try to do it without using your notes to see what sections you need to focus on when it comes time to study

Ionic – Names KBr Al2S3 MgO ZnS AlCl3 Ionic – Formulas
Potassium bromide Aluminum sulphide Aluminum chloride Magnesium oxide Zinc sulphide Ionic – Formulas Magnesium Chloride Potassium Nitride Sodium bromide Aluminum sulphide Aluminum chloride MgCl2 K3N NaBr Al2S3 AlCl3

tetraphosohorus hexaoxide diphosphorus pentaoxide
Molecular – Names P2O5 SO2 AsBr3 P4O6 CO Diphosphorus pentaoxide Arsenic tribromide Tetraphosphorus hexaoxide Carbon monoxide Sulphur dioxide Molecular – Formulas silicon dioxide carbon disulfide diboron tetrabromide tetraphosohorus hexaoxide diphosphorus pentaoxide SiO2 CS2 B2Br4 P4O6 P2O5

diphosphorus trioxide dinitrogen tetraoxide
Mixed – Names CS2 MgI2 KF N2O4 P4O6 Magnesium iodide Potassium flouride Dinitrogen tetraoxide Tetraphosphorus hexaoxide Carbon disulphide Mixed - Formulas Silicon dichloride magnesium chloride diphosphorus trioxide potassium nitride dinitrogen tetraoxide SiCl2 MgCl2 P2O3 K3N N2O4

Build the molecule using the ball and stick kits
Build the metal atom using the BR kit… how would you turn it into an ion? Draw a Bohr-Rutherford diagram of the reaction Draw a Lewis-dot structure of the reaction

End of chapter 7

Putting Atoms Together

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