Electrons in AtomsElectrons in AtomsElectron ConfigurationOrbital NotationLewis-Electron Dot Diagram

Essential question: What correlation is there between electron configuration and orbital notation?

Electron ConfigurationElectron ConfigurationA form of notation which shows how the

electrons are distributed among the various atomic orbital and energy levels

◦Example of e- configuration for Hydrogen: 1s1

Principle Quantum number which stands for the energy level

S-Block

Total # of electrons in that sublevel. 1st column of s-block

Essential question: What correlation is there between electron configuration and orbital notation?

Periodic PatternsPeriodic Patterns Yellow represents the s-block Pink represents the p-block Green represents the d-block Orange represents the f-block

S-block

S-block

p-block

d-block

f-block

Learning CheckLearning CheckWhat element would have an

electron configuration ending in 4s1?

Potassium

Order of filling sublevelsOrder of filling sublevels1s2 2s2 2p6 3s2 3p6 4s2

You must fill in each sublevel with its maximum number of electrons before you move to the next energy level

Sublevel (block)

# of orbitals Maximum # of e-

S 1 2

p 3 6

d 5 10

f 7 14

ExamplesExamplese- configuration for Oxygen

◦Oxygen has 8 electrons and is in period 2

◦1s2

2s2 2p4 6 valence electrons

2 energy level and located in the p-block

PracticePracticeWrite the e- configuration for the

following elements:

◦Helium◦Neon◦Sulfur◦Calcium

Orbital NotationOrbital Notation

Every box represents an orbitalEvery arrow represents electrons

Sublevel (block)

# of orbitals Maximum # of e-

S 1 2

p 3 6

d 5 10

f 7 14

General RulesGeneral RulesPauli Exclusion principle

◦ Every orbital can only hold 2 electrons with opposite spins

Hund’s rule◦ Within a sublevel, place one e- per orbital

before pairing them.

WRONG Right

Example:Example:

Orbital Notation for Oxygen:◦ You know the e- configuration for oxygen is

1s22s22p4

◦Remember: Every orbital is represented by a box Every orbital holds a maximum of 2

electrons s-block represented by 1 orbital p-block represented by 3 orbitals

1s2 2s2 2p4

PracticePracticeShow orbital notation for the

following elements:

◦Helium◦Neon◦Sulfur◦Calcium

Lewis Electron Dot StructureLewis Electron Dot Structure

An atom’s Lewis electron dot structure consists of :

◦ element’s symbol-which represents the atomic nucleus and inner-level electrons, surrounded by dots representing the atom’s valence electrons.

Source: Glencoe Chemistry Matter and Change pg. 140

Group 1A: 1 valence electron

How do we use the periodic table to draw Lewis electron dot structures?Identifying the representative group

number will allow you to determine the number of valence electrons.

Here’s how….

Group 2A: 2 valence electrons

Group 3A: 3 valence electrons

Group 4A: 4 valence electrons

Group 5A: 5 valence electrons

Group 6A: 6 valence electrons

Group 7A: 7 valence electrons

Group 8A: 8 valence electrons

Writing out Lewis Electron Dot Writing out Lewis Electron Dot StructureStructure

Group # = number of valence electrons

Example: Phosphorus is on group 5A, so it has 5 valence electrons.

PStep 1: write the element symbol

Step 2: Start at the top of the symbol and place one electron

Step 3: Continue placing one electron on each of the four sides of the symbol & then pair up the electrons until you have placed all valence electrons around the symbol

PracticePracticeWrite the Lewis Electron Dot

Structure for the following elements:

◦Helium◦Neon◦Sulfur◦Calcium

Questions??Questions??