Unit 3: Atomic Theory & Periodicity

Unit 3: Atomic Theory & Periodicity

Wednesday October 25th Warm-up: Pick up the Learning Targets
LEARNING OBJECTIVE 3.A: Atomic Information State the location & charge of each subatomic particle within the atom Use the periodic table to determine the number of protons, neutrons, and electrons in an atom of an element Define atomic number as it relates to subatomic particles Warm-up: Pick up the Learning Targets Highlight the quiz and test dates and copy them into your planner Pick up a periodic table

Video Take careful notes on the video, think about the learning targets as you are watching

Video Wrap up What are the 3 common particles in an atom?
What 2 particles are in the nucleus? If an atom were expanded to the size of a stadium what size would the nucleus be? What’s between the atom’s nucleus and the electrons? Where is the majority of the mass in an atom?

In your notes Particle Location in atom Charge Mass in AMU
Make a table in your notes to complete with the information you have learned. Particle Location in atom Charge Mass in AMU

Information from the Periodic Table
Number of Protons: same as atomic number Mass Number: listed as an AVERAGE on the periodic table. Calculated as number of protons plus the number of neutrons for individual atoms. Number of electrons in a neutral atom: same as number of protons Isotope/Atomic Notation:

Practice Write the atomic notation for a neutral atom of Oxygen-18
How many protons does it have? How many neutrons does it have? How many electrons does it have?

BOHR MODEL A Bohr Model is a simplified version of what an atom looks like. The protons and neutrons are located in the nucleus and the electrons are in “shells” or rings around the nucleus You draw a Bohr Model by placing two electrons maximum in the shell closest to the nucleus and a maximum of eight electrons in each of the other shells.

Steps for drawing a Bohr Model
1) count up the number of electrons, protons, and neutrons in your element 2) draw your nucleus with the number of protons and neutrons inside 3) draw and fill the first energy level with electrons (1st energy level can hold a max of 2 electrons) 4) if needed, draw and fill the 2nd level with electrons (2nd energy level can hold a max of 8 electrons) 5) If needed, draw and fill the 3rd level with electrons (3rd energy level can hold a max of 8 electrons – for now) 6) if needed, draw and fill the 4th level with electrons (4th energy level can hold a max of 8 electrons – for now) Your outermost energy level is your valence. The electrons in your outermost level are your valence electrons

Check in How many protons does Iodine (I) have?
How many protons does Tungsten (W) have? Which subatomic particle has a negative charge? What is the mass of one neutron? Where in an atom are electrons located? Draw a Bohr Model of a neutral atom of Sodium (Na) that has a mass of 23 AMU

LEARNING OBJECTIVE A: Atomic Information
Thursday October 26th LEARNING OBJECTIVE A: Atomic Information Warm-up: How many protons does Bromine (Br) have? How do you know? Write the atomic/isotope notation for Bromine-81 Independent Practice #1 is due on Monday 10/30

Answer to Warm-up Warm-up: How many protons does Bromine (Br) have?
How do you know? Write the atomic/isotope notation for Bromine-81 Answer: Bromine has 35 protons The atomic number for Bromine is 35. The atomic number is equal to the number of protons. The isotope/atomic notation is:

Isotopes Each person will need their own Isotopes packet and a periodic table. Choose a Facilitator & a Spokesperson. The facilitator will appoint a reader for the activity. The Spokesperson will appoint a clean up person for the activity. Work through carefully, making sure you reach consensus on each question. The spokesperson can check in with other groups or me if you get stuck.

Check in

Check in on our learning targets!
State the location and charges of each subatomic particle within the atom Use the periodic table to determine the number of protons, neutrons, and electrons in an atom Define atomic number as it relates to subatomic particles Define atomic mass as it relates to subatomic particles. Draw a Bohr Model of an atom, given its atomic notation Identify the number of valence electrons from a diagram or Bohr Model Explain and illustrate the concept of isotopes

How are they separated by mass?

I will be able to calculate average atomic mass.
Friday, October 27 LEARNING OBJECTIVE I will be able to calculate average atomic mass. WARM UP How many neutrons are in… Uranium-235 (atomic number 92) Lead-207 (atomic number 82) Hydrogen-3 (atomic number 1) What are isotopes?

today Relative Abundance Lab

Friday October 27 Exit Slip
Learning Objective I will be able to calculate average atomic mass. Exit Questions Why is average atomic mass so important it was included in the periodic table?

Monday October 30th Learning Objective: Atomic Information
- Average Atomic Mass & Relative Abundance Warm-up: Have Independent Practice Number 1 out REMINDER: Quiz 1 is TOMORROW

Steps for drawing a Bohr Model
1) count up the number of electrons, protons, and neutrons in your element 2) draw your nucleus with the number of protons and neutrons inside 3) draw and fill the first energy level with electrons (1st energy level can hold a max of 2 electrons) 4) if needed, draw and fill the 2nd level with electrons (2nd energy level can hold a max of 8 electrons) 5) If needed, draw and fill the 3rd level with electrons (3rd energy level can hold a max of 8 electrons – for now) 6) if needed, draw and fill the 4th level with electrons (4th energy level can hold a max of 8 electrons – for now) Your outermost energy level is your valence. The electrons in your outermost level are your valence electrons

Average Atomic Mass How do we calculate average atomic mass using abundancy?

1. The average atomic mass of nitrogen is 14. 0067 amu
1. The average atomic mass of nitrogen is amu. Predict which isotope listed below is most abundant in nature a. Nitrogen-13 b. Nitrogen-14 c. Nitrogen-15 2. A certain element was originally named “muriaticum” by its discoverer. This element exists on Earth as a mixture of two isotopes. The most abundant isotope (75.76%) has a mass of amu; the other isotope (24.24%) has a mass of amu. Calculate the average atomic mass and identify the element by its modern name. Wrap Up B When you calculate a simple average you assume equal representation by all the isotopes. Natural matter does not consist of isotopes with equal distribution so a weighted average is needed. (0.7576)( amu) + (0.2424)( ) = amu Chlorine

Answers B Nitrogen-14 (0.7576)( amu) + (0.2424)( ) = amu Chlorine

Monday October 31st Plan for today: Atomic Mass Warm-up Quiz #1
Start Half Life Lab Warm-up: Pick up Average Atomic Mass handout and begin working! This is our pre-quiz check in 

Quiz Clear your table of everything except something to write with, a calculator, and a periodic table. When you are done – pick up independent practice #2 from the front table. Independent Practice #2 is Due Thursday 11/2 100% = 1 50% = 0.5 1% = 0.01 0.1% = 0.001 0.01% =

Tuesday, October 31st Today you will work on a half-life lab
Complete the first page of the lab as a pair. (2 per table) Graph your data. Compare with the other pair at your table. Answer the follow up questions.

Have your lab and graph from yesterday out!
Wednesday November 1st Today you will finish your half-life lab and work through some practical examples. Have your lab and graph from yesterday out!

Half life calculations

Plan for today – Wednesday 11/1
Review Quiz #1 Half-Life Calculations & Practical Examples Begin talking about fission & fusion Gleb’s class plan for Monday

Thursday November 2nd Fission & Fusion Learning Targets
I can compare the energy outputs of fission and fusion reactions I can compare the energy outputs of fission and fusion to other energy transformations Warm-Up: A specific radioisotope takes 600 minutes to decay to 12.5% of its original mass. What is its half life?

Nuclear Reactions – some rules for fission & fusion
Mass must be conserved: atomic mass of the reactants must be equal to the atomic mass of the products Protons must be conserved: the total number of protons that go into the reaction (on the reactant side) must be the same total number that comes out of the reaction (on the product side) If the atomic number of an element changes, the element itself changes

Fission & Fusion (from your note packets)
A large nucleus is hit by something and splits into many smaller nuclei Usually Uranium-235 is hit by a neutron Recognizable because the largest mass will be on the reactants side of the equation Fusion: Two smaller nuclei are combined to make a larger nucleus Recognizable because the largest mass will be on the product side of the equation.

Fission

Independent Practice #2

Friday November 3rd Warm- Up: Clear your table for the quiz, you need a periodic table, a calculator maybe, and something to write with Pick up Independent Practice #3 after the quiz - Due 11/8 After the quiz, new learning target: Electron Configuration

Boarding House Model

What do the symbols mean?
= A person = Bunk bed for 2 people The big number (1, 2, 3) = The floor number s = The sunny room p = The pink room The exponents (1,2,3,4,5,6) = How many people are in that room on that floor

Rules from 3rd period People are added starting on the ground floor
Bottom bunk in each room must be occupied before any top bunks can be occupied Each room must be filled before anyone is placed in the next room rooms are filled from left to right Floors are filled from bottom to top No people in the kitchen No one is leaving

Rules from 2nd period Bottom sunny room must be filled before you can start filling another one People are added, but do not leave Sunny rooms are filled before the pink rooms on that level No doubling up until every bunk in that room has at least one person Filling left to right Fill bottom bunk before the top bunk Max of two people in a sunny room 6 in a pink room max No one can sleep in the kitchen 8 people max on 2nd and 3rd floor

Rules for filling the boarding house
Bottom floor fills up first Max of two people on first floor Max of 8 people on second & third floor No one can sleep in the kitchen Fill from left to right Bottom bunks fill first Sun rooms fill first, then the pink room No one shares a bunk bed until all of the bunk beds in that room have at least one person in them No one can sleep on the roof

Rules for filling the boarding house (generated by our class)
Start adding people on the lowest floor first 2 people can fit in each bunk bed You can not put someone in a top bunk until all of the bottom bunks in that room are full No one can sleep in the kitchen You must fill all the bunk beds on the current floor before you can move to the next highest floor Sunny room on that floor must be filled before pink room on that floor People are added gradually, no one leaves Add people from left to right in the room

What is the manager code for these three situations? A B C

Monday November 6th Learning Target D: Electron Energy Levels
Warm-up: Write the managers code for the following boarding house

Warm-up Solution

What do these symbols represent?

What do these symbols represent?
Orbital (a bunk bed) A single electron spinning up (one person) Two electrons with opposite spins (two people – one in bottom bunk one in top bunk) A sublevel (a room) Electron configuration (managers code)

Orbital Diagrams & Electron Configurations
Explain how electrons are arranged within the atom Show the order in which electrons are placed in orbitals Use boxes to represent orbitals Electron Configuration Short hand to show how many electrons are in an atom and at which energy level they will be found. Notes on these slides added for absent students

Electrons in Orbital Diagrams
To place electrons in orbital diagrams, electrons: are represented by arrows and the direction of the arrow is used to represent electron spin fill orbitals in order of increasing energy beginning with 1s, then 2s and 2p, then 3s and 3p Notes on these slides added for absent students

Electrons in Orbital Diagrams
Orbitals can hold a maximum of two electrons. Within sublevels that contain multiple orbitals, one electron is placed in each orbital with parallel spins before the electrons are paired. Notes on these slides added for absent students

Electron Configurations
Chemists use a notation called the electron configuration to indicate placement of electrons in an atom. The lowest energy sublevel is written first, then sublevels with increasing energies. The number of electrons in each sublevel is written as a superscript. Notes on these slides added for absent students

Period 1: Hydrogen and Helium
The 1s is written first; it has the lowest energy. Notes on these slides added for absent students

Period 2: Lithium to Neon
Period 2 begins with lithium, which has three electrons, 1s2 2s1. After the 2s is filled, the 2p orbitals are filled. One electron is placed in each p orbital before they are paired. An abbreviated configuration uses a noble gas in brackets to represent the filled electron configuration of that noble gas. [He] 2s1 Notes on these slides added for absent students

Period 2: Lithium to Neon
Notes on these slides added for absent students

Guide to Drawing Orbital Diagrams

Sample Problem Draw the orbital diagram for nitrogen. Step 1 Draw boxes to represent the occupied orbitals. Nitrogen has an atomic number of seven, which means it has seven electrons. Draw boxes to represent the 1s, 2s, and 2p orbitals. Notes on these slides added for absent students

Sample Problem Draw the orbital diagram for nitrogen. Step 2 Place a pair of electrons in the last occupied sublevel in separate orbitals. We place the remaining three electrons in the 2s orbitals. Notes on these slides added for absent students

Sample Problem Draw the orbital diagram for nitrogen. Step 3 Place remaining electrons with opposite spins in each filled orbital. First we place a pair of electrons with opposite spins in the 2p orbitals, with arrows in the same direction. Notes on these slides added for absent students

Period 3: Sodium to Argon
[Ne] is used to represent 1s2 2s2 2p6. Notes on these slides added for absent students

Period 3: Sodium to Argon

Draw the abbreviated orbital diagram for aluminum: [Ne] 3s2 3p1
Learning Check Draw the abbreviated orbital diagram for aluminum: [Ne] 3s2 3p1 Notes on these slides added for absent students

Solution Draw the abbreviated orbital diagram for aluminum, [Ne] 3s2 3p1. 1. The preceding noble gas is Ne; we use this to represent 1s2 2s2 2p6. 2. Fill the 3s, and add the last electron to the 3p sublevel. [Ne]

Tuesday November 7th Learning Target E: Ions Guiding Question: How are ions made from neutral atoms? Warm-up: Write the ground state electron configuration for a neutral atom of Chlorine

Warm-up Solution Chlorine has 17 electrons in a neutral state (atomic number of 17 = 17 protons, to be neutral it would need 17 electrons) Ground state electron configuration for a neutral atom of Chlorine: 1s22s22p63s23p5 or [Ne] 3s23p5 How should I check my work? Each s sublevel can only have two electrons Each p sublevel can only have a maximum of 6 electrons The exponents should add up to 17. Chlorine is in the 3rd row of the periodic table and the p5 column so the electron configuration should end in 3p5

What do we want to accomplish today?
Review the last quiz Ionization – understand how ions are made from neutral atoms Calculate the charge of ions Calculate how many electrons are present from the ion notation Identify columns on the periodic table with specific ion charges Know the difference between cations & anions Know the difference between oxidation and reduction Write electron configurations and ion configurations

How do we calculate the charge on an ion?
The charge on an atom or ion is equal to its number of protons minus its number of electrons Charge = (# of Protons) - (# of Electrons) Example: An atom with 17 protons and 18 electrons has a charge of -1 Cl1- Notes added for students who were absent

What is an ion? An ion is a charged particle. Instead of being neutral, our ion has either a positive or a negative charge Ions are formed when atoms gain or lose electrons. Positive ions are called cations. They are formed when a neutral atom loses electrons. Negative ions are called anions. They are formed when a neutral atom gains electrons. Metallic atoms tend to lose electrons to form positive ions/cations. Nonmetallic atoms tend to gain electrons to form negative ions/anions. Notes for students who were absent

How do we indicate that an element is in its ion form?
Charge is listed on the top right side of the atomic/isotope notation: Cl1- Ion configuration includes the gained or lost electrons For an ion of chlorine the ion configuration would be: 1s22s22p63s23p6 or [Ne] 3s23p6 or [Ar]

Ionization wrap up Ionization is losing or gaining electrons to get to a full valence shell. If an element has less than 4 electrons in the valence it will lose electrons, if it has more than 4 electrons it will gain electrons. This is called the octet rule. Elements want to have 8 valence electrons

Oxidation & Reduction If an element loses electrons it is OXIDIZED
If an element gains electrons it is REDUCED LEO the lion says GER LEO= Loss of Electrons is Oxidation GER= Gain of Electrons is Reduction

Magnesium- write the electron configuration and ion configuration

What do we want to accomplish today?
Review the last quiz Ionization – understand how ions are made from neutral atoms Calculate the charge of ions Calculate how many electrons are present from the ion notation Identify columns on the periodic table with specific ion charges Know the difference between cations & anions Know the difference between oxidation and reduction Write electron configurations and ion configurations

Wednesday November 8 Learning Target: Electron Dot Diagrams & Ion Configuration Warm-up: How many valence electrons does a neutral atom of Nitrogen-15 have? How do you know?

Warm-up Warm-up: How many valence electrons does Nitrogen have? How do you know? How many ways can you show that Nitrogen has 5 valence electrons? Bohr Model Orbital Diagram Electron Configuration What group it is in on the periodic table Ion configuration

For Today Electron/Ion Configurations for first 20 elements
Electron Dot Diagrams on white boards Review Independent Practice #3

Ionization – review from Yesterday
Ionization is losing or gaining electrons to get to a full valence shell. If an element has less than 4 electrons in the valence it will lose electrons, if it has more than 4 electrons it will gain electrons. This is called the octet rule. Elements want to have 8 valence electrons

Oxidation & Reduction If an element loses electrons it is OXIDIZED
If an element gains electrons it is REDUCED LEO the lion says GER LEO= Loss of Electrons is Oxidation GER= Gain of Electrons is Reduction The ion charges that form are called “oxidation states”

Electron Dot Diagrams

Thursday Plan for today: Time to review Quiz #3 Electron Dot Diagrams
Pick up Independent Practice #4 Due 11/16 Notes on Periodic Table if we have time 

Quiz Clear your table except for a periodic table, something to write with, and a calculator. SHOW ALL YOUR WORK.

Lewis Dot Diagrams Pick up the Lewis Dot Diagram activity – we will breeze through this and check in as a group.

New Vocabulary: Group & Period
On your periodic table you have Groups & Periods the horizontal rows are called periods (energy levels) the vertical columns are called groups (families) The main groups are numbered from 1A to 8A going from left to right The block in between Group 2A and Group 3A is where the transition metals are placed

Why does this matter? Elements in the same group have similar chemical properties – however, their reactivity can vary. Your labs next week will help you to answer the question: How does the position of an element in a column on the periodic table affect the reactivity of that element?

Monday November 13th Properties of Elements – you will need a jacket, we’re going outside near the end of class. Warm-up: draw the Bohr Models for Lithium, Sodium, and Potassium

Tuesday November 14th Learning Target: Trends in Reactivity
You will need goggles, something to write with, your notes, and the lab handout.

Lab Write your hypothesis to answer the testable question
Perform your experiments to test your hypothesis (you might want to use a flashlight to see the reaction better!) Record your data (you should see a minimum of 4 reactions) Write up your procedure and your conclusion Due tomorrow: procedure, data, conclusion (1 per group)

Monday - November 14 Lithium Sodium Potassium
Learning Target H: Discuss the properties of Alkali Metals Learning Target G: Describe the trend in atomic radius as you move from left to right and top to bottom of the periodic table Warm-up: Draw the Lewis Dot Diagrams for the following metals: Lithium Sodium Potassium

Some new terms! Ionization Energy: The amount of energy needed to remove an electron from an atom First Ionization Energy: The amount of energy needed to remove the MOST loosely held electron from an atom in its ground state Electronegativity (sometimes called Electron Affinity): The energy change for the process of adding an electron to an atom. How much an atom would like to gain an electron. Atomic Radius: Distance from the nucleus to the outermost energy level (valence electrons)

Block Day - November 14 & 15 Learning Objective 3.D: Periodic Trends
Warm-up: Have your lab procedure out and grab some goggles!

Plan for Today Reactivity Lab Atomic Properties Posters

Lab wrap up Did your lab results match your expectations? Explain.
List the tested elements in the order they are found on the periodic table. List the elements in order of least reactive to most reactive. If you had a radium compound in this lab, how would you expect its reactivity to compare to the calcium, magnesium, and strontium compounds? Explain why. What scientific reason would you provide for your results if you were writing a conclusion?

Properties of Groups Poster
Your table group will make two posters that explains the properties of 1 of the periodic groups. Your first poster should have: The name of the group The number of the group How many valence electrons elements in the group have What elements make up the group At least one fact about the group Trends in atomic radius, electronegativity, and first ionization energy for your group The SECOND POSTER: The specific atomic radius, electronegativity, and first ionization energy of your FIRST element in the group At the end of the class we will rotate around and complete our notes using the posters

Notes from Posters What is the trend in electronegativity ACROSS the periodic table and DOWN the groups? What is the trend in first ionization energy ACROSS the periodic table and DOWN the groups? What is the trend in atomic radius ACROSS the periodic table and DOWN the groups?

1a & 2a Periodic Table Groups - Alkali Metals - Group 1 Alkali metals are elements found in group 1 of the Periodic Table. Alkali metals are soft, malleable, ductile, and are good conductors of heat and electricity. They have Low melting and boiling points compared to most other metals. The names of these elements are Lithium, Sodium, Potassium, Rubidium, Cesium and Francium. They are silver- colored when pure and soft. Elements classified as Alkali Metals are very reactive metals that do not occur freely in nature. Periodic Table Groups - Alkaline Earth metals - Group 2 Alkaline Earth metals are the elements in group 2 of the Periodic Table. The chemical symbols identify the element names. The alkaline earth metals are silvered colored, soft metals. Elements classified as Alkaline Earth Metals are all found in the Earth’s crust, but not in the elemental form as they are so reactive. Instead, they are widely distributed in rock structures. Alkaline metals are usually shiny solids that conduct heat or electricity and can be formed into sheets.

7a & 8a Periodic Table Groups - Halogens - Group 7a The 5 elements classified as "Halogens" are located in Group 7a of the Periodic Table. They are non-metals with low melting and boiling points. They have colored vapors and are poor conductors of heat and electricity. The elements classed as Halogens are Fluorine, Chlorine, Bromine, Iodine and Astatine. Periodic Table Groups - Noble Gases - Group 8a The Noble Gases are in Group 8a of the periodic table. All of these gases are found in air and make up around 0.96% of the atmosphere. They are very un- reactive and colorless gases The 6 elements classed as noble gases are Helium, Neon, Argon, Krypton, Xenon and Radon.

Thursday November 16 Learning Target: Periodic Trends – atomic radius, valence electrons, electronegativity, ionization energy Warm-up: Write the electron configuration for a neutral atom of Carbon. Circle the final orbital notation in your configuration. Example: The electron configuration for a neutral atom of sulfur is: 1s22s22p63s23p4

Periodic Trends Orbital Notation & The Periodic Table
Assessment #1 If correct  Go on to Coulombic Attraction If not yet correct  Electron Configuration Practice Sheet Coulombic Attraction Assessment #2 If correct  Go on to Periodic Trends If not yet correct  Review Coulombic Attraction, write a list of rules for identifying strength of Coulombic attraction Periodic Trends (model 1 is a separate sheet – make sure you get both  ) – no extension problems Assessment #3 During each activity: Use the post-it notes to make a claim, provide evidence, and list a scientific reason for the 4 periodic trends we are discussing today. A sample claim format has been listed on the board for you! Each group should make at least 1 claim, 1 evidence, and 1 reason. That is 3 post-it notes total 

Assessment #1 If correct  Go on to Coulombic Attraction If not yet correct  Electron Configuration Practice Sheet Coulombic Attraction Assessment #2 If correct  Go on to Periodic Trends If not yet correct  Review Coulombic Attraction, write a list of rules for identifying strength of Coulombic attraction Periodic Trends – no extension problems Assessment #3

Friday 11/17 Goal: Complete all three assessments
Guiding Question: What is the scientific reasoning for the trends found on the periodic table? Goal: Complete all three assessments Some quick check in notes Take Quiz #4 Pick up study guide Study for exam on Tuesday 11/21

Assessment #1 If correct  Go on to Coulombic Attraction If not yet correct  Electron Configuration Practice Sheet Coulombic Attraction Assessment #2 If correct  Go on to Periodic Trends If not yet correct  Review Coulombic Attraction, write a list of rules for identifying strength of Coulombic attraction Periodic Trends – no extension problems Assessment #3

What trends did we observe on the periodic table?
A trend must be explained both across a period on the periodic table (from left to right on the row) and down a group on the periodic table (from top to bottom on a column) We observed trends in: Atomic Radius Electronegativity Ionization Energy Reactivity Orbital Notation Notes for students who were absent

Why? Coulombic Attraction!
Trend in Atomic Radius Atomic Radius increases as you move down a group and decreases as you move (L-R) across a period (in general) Why? Coulombic Attraction! Adding energy levels (electron shells) on to the atom increases its size so as you move down a group, each energy level increases the radius of the atom. When the energy level stays the same (across a period) more protons are added and attract the valence electrons closer to the nucleus, this decreases the radius. Notes for students who were gone

Trend in Electronegativity
Electronegativity decrease as you move down a group and increases as you move (L-R) across a period (except Nobel Gases) Why? Atomic Radius! Sort of! Simplified version : Increased atomic radius makes it harder for the atom to attract electrons. As the radius increases, the electronegativity decreases. As the radius decreases, the electronegativity increases because the atom is more able to attract electrons. Notes for students who were gone

Trend in Ionization Energy
Ionization Energy decrease as you move down a group and increases as you move (L-R) across a period (except Nobel Gases) Why? Atomic Radius! Sort of! Simplified version : Increased atomic radius makes it harder for the atom to hang on to its electrons. As the radius increases, the ionization energy decreases. As the radius decreases, the ionization energy increases because the atom is more able to hang on to its electrons and it takes more energy to remove them. Notes for students who were gone

Trends in Reactivity Why?
For metals, we observed that reactivity increases as you move down a group and decreases as you move (L-R) across a period. For nonmetals, we observed that reactivity decreases as you move down a group and increases as you move (L-R) across a period. Why? Metals want to donate their electrons, so their reactivity is based on ionization energy. Lower ionization energy means more reactive. Non-Metals want to gain electrons, so their reactivity is based on electronegativity. Higher electronegativity means more reactive. Notes for students who were gone

Orbital Notation When writing electron configurations for neutral atoms, the final orbital notation will align with the element’s location on the periodic table. Coefficient = period number for s & p OR period minus 1 for d OR period minus 2 for f. Letter = block of the table Exponent = column in that block Example: Gallium : 1s22s22p63s23p64s23d104p1 the final orbital notation is: 4p1 So Gallium will be found in the 4th period (row) in the first column of p-block Notes for students who were absent

Why do elements in the same group have similar chemical properties?
Chemical reactions are determined by the number of valence electrons! Elements in the same group have the same number of valence electrons, so they behave in similar ways.

Thursday November 17 For the quiz – periodic table, calculator, pencil
After the Quiz: Get your goggles and a lab printout! Read through the lab printout and have a separate sheet of paper out for your observations and answers to the questions.

Flame Test Lab Just as a fingerprint is unique to each person, the color of light emitted by an element heated in a flame is unique to each element. When a substance is heated in a flame, the atoms absorb energy from the flame. This absorbed energy allows the electrons to be promoted to excited energy levels. From these excited energy levels, the electrons will eventually drop down to their original energy level. When an electron drops from a higher energy level to a lower energy level, a particle of light called a photon is emitted. The energy of the photon determines the color of the flame that you can observe. Because each element has a different spacing of electron energy levels (or shells), the possible color of flames that can be emitted are unique to each substance.

Flame Test Lab In this experiment you will observe the light signature of 6 different samples. Once you have observed the samples you will use the data you collected to identify an unknown sample.

Friday November 18 Plan for today: Claim, Evidence, Reasoning
Learning Target: Periodic Trends – Claim, Evidence, Reasoning Plan for today: Claim, Evidence, Reasoning Work on Study Guide! Upcoming Dates: Exam on Tuesday November 22nd Study Guide Due Tuesday November 22nd

Claim. Evidence. Reasoning.

Claim A statement that you believe to be true.
“As you go down a group on the periodic table, the number of valence electrons stays constant. As you go across a period on the periodic table, the number of valence electrons increases.”

Evidence Evidence: How do you know? A statement that supports your claim. In the group 1A elements, Lithium, Sodium, Potassium, and Rubidium all have one valence electron. In period 2, Lithium has 1 valence electron, Beryllium has 2, Aluminum has 3, Silicon has 4, and Phosphorous has 5.

Reasoning Reasoning: Explain your claim and evidence with scientific fact. When you move across a period on the periodic table, the atomic number increases by 1. This increases the proton number by 1, and for the atom to be neutral, it also increase the electron number by 1. Once you get to the end of the period where the noble gas is located, the valence shell is full and another has to be added. In the next period you restart with a new valence shell with 1 electron and the pattern continues.

Monday 11/20 Warm-up (please solve on your own in your notes) Three isotopes of argon occur in nature – Ar-36, Ar- 38, Ar-40. Calculate the average atomic mass of argon, given the following relative atomic masses and abundances of each of the isotopes: Ar-36 (35.97amu; %), Ar-38 (37.96amu; 0.063%), and Ar-40 (39.96amu; %).

Monday November 20th Plan for today: Review Quiz #4
Study guide – last chance to ask questions and check the key Prepare for tomorrow’s exam

Relative Atomic Mass Naturally occurring boron is 80.20% boron-11 (atomic mass = 11.01amu) and 19.80% of some other isotopic form of boron. What must the atomic mass of this second isotope be in order to account for the amu average atomic mass of boron?

Bohr Model & Valence Electrons
Draw a bohr model of a neutral atom of Calcium-40 How many valence electrons does a neutral atom of Calcium-40 have?

Ionization If calcium ionizes, will it gain or lose electrons?
Why? Write the ion notation for an ionized calcium Which is larger, the atomic radius of a neutral calcium or the atomic radius of an ionized calcium?

Electron Configuration
Write the electron configuration for a neutral atom of Potassium How can we check that it is right? Write the ion configuration for an ionized atom of Potassium

Atomic Information State the location and charges of each subatomic particle within the atom Use the periodic table to determine the number of protons, neutrons, and electrons in an atom Define atomic number as it relates to subatomic particles Define atomic mass as it relates to subatomic particles. Draw a Bohr Model of an atom, given its atomic notation Identify the number of valence electrons from a diagram or Bohr Model

Isotopes and Relative Atomic Mass
Explain and illustrate the concept of isotopes Explain the concept of relative atomic mass Calculate the atomic mass of an element, given the mass and abundance of isotopes Use isotope notation to determine the number of protons, neutrons, and electrons for an isotope Write an isotope symbol when given info about the number of subatomic particles in an isotope

Nuclear Reactions Describe half-life as the amount of time it takes for half of a radioactive sample to decay Perform basic half-life calculations Compare the energy outputs of fission and fusion reactions Compare the energy outputs of fission and fusion to other energy transformations

Energy Levels and Electron Configuration
State the energy sublevels within an energy level State the maximum number of electrons that can occupy a given energy level and sublevel List the order of sublevels according to increasing energy Write the predicted electron configuration for the first 20 elements Identify the number of valence electrons from an electron configuration

Ions Describe how distance effects the attraction between protons and electrons Describe the formation of ions as either a gain or loss of electrons Describe the formation of ions in terms of oxidation and reduction Determine ion charge based on the number of valence electrons present in the neutral atom Predict the ion charge based on location on the periodic table Write Isotope notation for ions Determine if an ion is a cation or anion

Groups and Periods on the Periodic Table
Define group as it relates to the periodic table. Define period as it relates to the periodic table.

Periodic Trends Trends in valance electrons as you move from left to right and top to bottom on the periodic table. Trend in atomic radius as you move from left to right and top to bottom of the periodic table. Trend in electronegativity as you move from left to right and top to bottom of the periodic table. Trends in ionization energy as you move from left to right and top to bottom of the periodic table.

Properties of Elements
Discuss the properties of alkali metals. Discuss the properties of alkali earth metals. Discuss the properties of halogens. Discuss the properties of noble gasses.

Tuesday November 22nd Exam Day! Hooray!
Clear your table of everything except: Study Guide (stack all study guides on the corner of your table) Something to write with (pen or pencil) Calculator (no phones) I am providing the periodic table 

Unit 3: Atomic Theory & Periodicity

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Unit 3: Atomic Theory & Periodicity

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Presentation on theme: "Unit 3: Atomic Theory & Periodicity"— Presentation transcript:

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