Electrons in AtomsChapter 5

I CAN…Write long-hand electron

configurationsWrite short-hand (Nobe Gas)

electron configurationsDraw s and p orbitalsMatch the scientist with their

contributions to the electron cloud model

Draw electron hotels! (energy level diagrams)

Announcements 12/10HW: From the PPT later onLab later this week, date TBA

(probably on Thursday)Grades

In class: Finish writing the electron configurations for each of the following:

1. Nitrogen – 1s2 2s2 2p3

2. Chlorine – 1s2 2s2 2p6 3s2 3p5 3. Sodium4. Ruthenium5. Gallium6. Cesium7. Silicon8. Iodine9. Vanadium

Check your work:1. Nitrogen – 1s2 2s2 2p3

2. Chlorine – 1s2 2s2 2p6 3s2 3p5 3. Sodium - 1s2 2s2 2p6 3s1 4. Ruthenium - 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d6

5. Gallium – 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1 6. Cesium – 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1

7. Silicon – 1s2 2s2 2p6 3s2 3p2 8. Iodine – 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10

5p5 9. Vanadium – 1s2 2s2 2p6 3s2 3p6 4s2 3d3

This fills the valenceshell and tends to givethe atom the stabilityof the inert / noble gases.

The Octet RuleAtoms tend to gain, lose, or share electrons until they have eight valence electrons.

8

ONLY s- and p-orbitals are valence electrons.

• Shorthand Configuration

S 16e- Valence ElectronsCore Electrons

S 16e- [Ne] 3s2 3p4

1s22s22p63s23p4

NotationLonghand Configuration

Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

S32.066

16

Noble Gas ConfigurationNoble Gases have their outer shell

full; therefore, we can use the noble gas configuration as short hand.

Look for Noble Gas before atom you want. Sodium – has Neon before.

Ne = 1s2 2s2 2p6

Na = 1s2 2s2 2p6 3s1

Na = [Ne] 3s1

neon's electron configuration (1s22s22p6)

Shorthand Configuration

[Ne] 3s1third energy level

one electron in the s orbital

orbital shape

Na = [1s22s22p6] 3s1electron configuration

A

B

C

D

Write Noble Gas Configurations for each below:Aluminum

Bromine

Barium

Cobalt

Lead

Potassium

Check your work:Aluminum – [Ne] 3s23p1

Bromine – [Ar] 4s2 3d104p5

Barium – [Xe] 6s2

Cobalt – [Ar] 4s23d7

Lead – [Xe] 6s24f145d106p2

Potassium – [Ar] 4s1

Bohr Model

Nucleus

ElectronOrbit

Energy Levels

Bohr Model

Nucleus

ElectronOrbit

Energy Levels

Quantum Mechanics Heisenberg Uncertainty Principle

› Impossible to know both the velocity and position of an electron at the same time

Microscope

Electron

g

Werner Heisenberg~1926

The Electron as a WaveSchrödinger’s Wave Equation

› Used to determine the probability of finding the H electron at any given distance from the nucleus

› Electron best described as a cloud Effectively covers all points at the same time

(fan blades)

Electronorbitals

EquivalentElectronshells

(a) 1s orbital (b) 2s and 2p orbitals c) Neon Ne-10: 1s, 2s and 2p

1999, Addison, Wesley, Longman, Inc.

Electron Orbitals: