Unit 03 The Modern Atom

Quantum Mechanical Model Quantum mechanics was developed by Erwin Schrodinger Estimates the probability of finding an e - in a certain position Electrons are found in an “electron cloud” or orbital

Radial Distribution Curve Orbital Orbital (“electron cloud”) –Region in space where there is 90% probability of finding an e -

Each orbital letter has a different shape.

“s” orbital spherical shaped 1 orbital

“p” orbital Dumbbell shaped Arranged x, y, z axes 3 orbitals

“d” orbital clover shaped 5 orbitals

“f” orbital f Orbitals combine to form a spherical shape. 2s 2p z 2p y 2p x 7 orbitals

Hog Hilton You are the manager of a prestigious new hotel in downtown Midland—the “Hog Hilton”. It’s just the “snort of the town” and you want to keep its reputation a cut above all the other hotels. Your problem is your clientele. They are hogs in the truest sense. Your major task is to fill rooms in your hotel. The Hog Hilton only has stairs. You must fill up your hotel keeping the following rules in mind: 1) Hogs are lazy, they don’t want to walk up stairs! 2) Hogs want to room by themselves, but they would rather room with another hog than walk up more stairs. 3) If hogs are in the same room they will face in opposite directions. 4) They stink, so you can’t put more than two hogs in each room.

Hog Hilton Your hotel looks like the diagram below: 6th floor ________ 5th floor ________ ________ ________ 4th floor ________ 3rd floor ________ ________ ________ 2nd floor ________ 1st floor ________ Book 7 hogs into the rooms.

Hog Hilton Your hotel looks like the diagram below: 6th floor ________ 5th floor ________ ________ ________ 4th floor ________ 3rd floor ________ ________ ________ 2nd floor ________ 1st floor ________ Book 14 hogs into the rooms.

Choose 3 Days of the week and Draw them in the left side of your spiral. 6th floor ______ 5th floor ______ ______ ______ 4th floor ______ 3rd floor ______ ______ ______ 2nd floor ______ 1st floor ______ Hog Hilton = ↑ = ↓

Let’s play Hog Hilton!!

Now you will relate the “Hog Hilton” to electron orbitals. Electron orbitals are modeled by the picture on the left and are grouped into principal energy levels. 1. Compare their similarities and differences. 2. To go between floors on the Hog Hilton did the hogs need to use energy? Would electrons need to use the energy to go between orbitals? 3d ___ ___ ___ ___ ___ n=3 (4s ____) n=4 3p ___ ___ ___ n=3 3s ___ n=3 2p ___ ___ ___ n=2 2s ___ n=2 1s ___ n=1 6th floor ___ 5th floor ___ ___ ___ 4th floor ___ 3rd floor ___ ___ ___ 2nd floor ___ 1st floor ___

A. Rules for e - configurations Aufbau principle 1. Aufbau principle: electrons fill the lowest energy orbitals first. ( Hogs are lazy, they don’t want to walk up stairs!)

A. Rules for e - configurations 2. Pauli Exclusion principle TWO 2. Pauli Exclusion principle: each orbital can hold TWO electrons with opposite spins (They stink, so you can’t put more than two hogs in each room. & If hogs are in the same room they will face in opposite directions.)

RIGHT WRONG A. Rules for e - configurations 3. Hund’s rule 3. Hund’s rule: within a sublevel, place one e - per orbital before pairing them. ( Hogs want to room by themselves, but they would rather room with another hog than walk up more stairs.)

4p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ___ 3p ___ ___ ___ 3s ___ 2p ___ ___ ___ 2s ___ 1s ___ B. Drawing Orbitals Krypton ↑↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓↓↓↑↓↑↓ ↑↑↑↓↓↓

4p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ___ 3p ___ ___ ___ 3s ___ 2p ___ ___ ___ 2s ___ 1s ___ White Board Practice: Drawing Orbitals Chlorine ↑↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓↓

4p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ___ 3p ___ ___ ___ 3s ___ 2p ___ ___ ___ 2s ___ 1s ___ White Board Practice: Drawing Orbitals Nickel ↑↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓↓↓↑↑

C. Writing the Electron Configuration 4p _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 3d _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 4s _ ↑↓ _ 3p _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 3s _ ↑↓ _ 2p _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 2s _ ↑↓ _ 1s _↑↓_ 1s 2 Krypton: atomic number s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 Add the exponents to check your answer Exponent is number of e-

4p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ___ 3p ___ ___ ___ 3s ___ 2p ___ ___ ___ 2s ___ 1s ___ White Board Practice: Writing Electron Configurations Iron Fe – atomic number 26 ↑↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↓↑↑↑ 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 1s 2 Add the exponents to check your answer

4p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ___ 3p ___ ___ ___ 3s ___ 2p ___ ___ ___ 2s ___ 1s ___ White Board Practice: Writing Electron Configurations Sulfur S – atomic number- 16 ↑↓ ↑↓ ↑↑↑↓↓↓ ↑↓ ↑↑↑↓ 2s 2 2p 6 3s 2 3p 4 1s 2 Add the exponents to check your answer

1s 2s 2p 3s 3p ___ ___ ___ ___ ___ ___ ___ ___ ___ Worksheet: Electron Configurations Aluminum atomic number - 13 Al Electron Configuration:___________________ ↑↓↑↓↑↑↑↓↓↓↑↓ 2s 2 2p 6 3s 2 3p 1 1s 2 ↑

6767 e- config. Periodic Patterns s p d (n – 1) f (n – 2) n = Principle energy level (Period #)

What is the electron configuration for Br? 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 Br p 5

What is the electron configuration for Sulfur? 1s 2 2s 2 2p 6 3s 2 3p 4 S

What is the electron configuration for Titanium? 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2 Ti

What element has the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 4 ? Add together all the exponents, then find that atomic number. = Sulfur 16

How many electrons are present in the d sublevel of a neutral atom of Manganese? Learning Check electrons

D. Noble Gases Shorthand Use the noble gas in the previous row. Write noble gas symbol in brackets then rest of the e-configuration.

zShorthand Configuration S 16e - 1s 2 2s 2 2p 6 3s 2 3p 4  Longhand Configuration S16e - [Ne]3s 2 3p 4

[Ne] 3s 2 3p 2 Noble Gas Shorthand Ex – Silicon

[Ar] 4s 2 3d 10 4p 2 Noble Gas Shorthand Ex - Germanium

[Xe] 6s 1 Noble Gas Shorthand Ex - Cesium

Learning Check Use Noble Gas Shorthand write the e - config. 1. Cr 2. Br 3. Sn 4. Ba [Ar] 4s 2 3d 4 [Ar] 4s 2 3d 10 4p 5 [Kr] 5s 2 4d 10 5p 2 [Xe] 6s 2

Learning Check 1. Which orbital quantum number combination is not possible? A. 2s B. 2d C. 4d D. 3p

2. How many electrons are required to fill the 1st energy level? A. 2 B. 4 C. 8 D. 10 Learning Check

3. How many electrons are required to fill the 2 nd energy level? A. 2 B. 4 C. 8 D. 10 Learning Check

4. How many electrons are required to fill the 3 rd energy level? A. 4 B. 8 C. 10 D. 18 Learning Check

7s 7p 7d 7f 6s 6p 6d 6f 5s 5p 5d 5f 4s 4p 4d 4f 3s 3p 3d 2s 2p 1s Correct orbital filling order

The trick to f orbitals! Examples: Erbium- Er 68 Hassium- Hs [Xe] 6s 2 4f 11 5d 1 [Rn] 7s 2 5f 14 6d 6

Learning Check Use Noble Gas Shorthand write the e - config. 1. Sm 2. Db [Xe] 6s 2 4f 5 5d 1 [Rn] 7s 2 5f 14 6d 3

II. Quantum Numbers UPPER LEVEL Four Quantum Numbers: –Specify the “address” of each electron in an atom

1. Principal Quantum Number ( n ) –Energy level –Size of the orbital –n 2 = # of orbitals in the energy level II. Quantum Numbers

s p d f 2. Angular Momentum Quantum # ( l ) –Energy sublevel –Shape of the orbital

II. Quantum Numbers n=# of sublevels per level n 2 =# of orbitals per level Sublevel sets: 1 s, 3 p, 5 d, 7 f Principal energy level (n) Number of sublevels Names of Sublevels 1 st energy level1 sublevel“s” (1 orbital) 2 nd 2 sublevels“s” (1) & “p” (3 orbitals) 3 rd 3 sublevels“s”(1), “p” (3) & “d” (5 orbitals) 4 th 4 sublevels“s”(1), “p”(3), “d”(5), and “f” (7)

II. Quantum Numbers 3. Magnetic Quantum Number ( m l ) –Orientation of orbital –Specifies the exact orbital within each sublevel

II. Quantum Numbers pxpx pypy pzpz

4. Spin Quantum Number ( m s ) –Electron spin  +½ or -½ –An orbital can hold 2 electrons that spin in opposite directions. +½-½

II. Quantum Numbers 1. Principal #  2. Ang. Mom. #  3. Magnetic #  4. Spin #  energy level sublevel (s,p,d,f) orbital electron –No two electrons in an atom can have the same 4 quantum numbers. –Each e - has a unique “address”:

A. Oxidation States Valence electrons – the outer electrons in an atom that are involved in chemical bonding Octet Rule - when forming compounds atoms want to have 8 e - (s 2 p 6 ) like the noble gases (except He)

A. Oxidation States A “+” means lose electrons A “–” means gains electrons Determine the element’s behavior in the company of other elements Some elements only have one oxidation state, others have several The transition metals generally have several oxidation states

B. Justifying Oxidation States Metals lose e - to either minimize e - to e - repulsions or eliminative their valence e - entirely Nonmetals tend to gain electrons to acquire an octet of electrons –(8 valence e - arranged as ns 2 np 6 where n = principle energy level) –Noble gases have octet naturally Transition metals have oxidation state of +2 since they lose the s 2 that was filled just before the d- sublevel began filling 3d e- are similar in energy to 4s e - & 4d are similar to 5s, etc.

Example 1: Sulfur have many oxidation states. Use an orbital notation to justify its most common -2 oxidation state: Sulfur is a nonmetal and tends to gain e - creating the -2 charge. Gaining 2 e - gives it an octet of 3s 2 3p 6. B. Justifying Oxidation States 3s ___ 3p ___ ___ ___ ↑↓↑↓↑ ↑ [Ne]

Example 2: Copper has two common oxidation states, +2 and +1. Justify both oxidation states: Cu has an ending e - conf. of 4s 2 3d 9. Start by drawing its orbital notation of the outermost, valence electrons. Since Cu is a transition metal, the +2 oxidation state come from losing the 4s e - s leaving 4s 0 3d 9. The +1 oxidation state for Cu come from transferring one of the s e - s to the d orbitals to fill that sublevel and then losing the remaining s e- to form 4s 0 3d 10. B. Justifying Oxidation States 4s 3d ___ ___ ___ ↑ [Ar] ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑ ↑

7s 7p 7d 7f 6s 6p 6d 6f 5s 5p 5d 5f 4s 4p 4d 4f 3s 3p 3d 2s 2p 1s 1 st Principle Energy Level – 1 sublevel 2 nd Principle Energy Level – 2 sublevels 4p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ___ 3p ___ ___ ___ 3s ___ 2p ___ ___ ___ 2s ___ 1s ___ s– 1 orbital p – 3 orbitals d – 5 orbitals Principle Energy level – large number in front Sublevel – # and letter (orbital) 3 rd Principle Energy Level – 3 sublevels 4 th Principle Energy Level – 4 sublevels Recap from yesterday