ii. quantum theory. a. review of atomic theory thomson discovered the electrons bohr determined...

II. Quantum Theory

A. Review of Atomic TheoryThomson

Discovered the electronsBohr

Determined electrons travel around the nucleus according to energy; electrons with lower energy are closer to the nucleus

Quantum Mechanical Model or Electrons Cloud ModelElectrons orbit the nucleus in

“clouds”; high probability of finding them somewhere along these paths

B. Electron ConfigurationElectron can jump multiple levels:

1 energy level (red light) 2 energy levels (green light) 3 energy levels (blue light) 4 energy levels (violet light)

B. Electron Configuration Cont.Electrons orbit in specific energy

levels.There are seven energy levelsLowest energy level = smallest

and the closest to the nucleusEach energy level has a specific,

limited number of electrons

C. Energy Levels, Sublevels, & Orbitals

The lowest energy level is n = 1

On the periodic table, each period (horizontal row) is an energy level

1234567

C. Energy Levels, Sublevels, & Orbitals

Each energy level has energy sublevels: s, p, d, f

Each energy sublevel has different number of orbitalsOrbitals: 3-D clouds where

electrons are found 90% of the time

Each orbital can hold 2 electrons

s sublevel = 1 orbital (2 electrons)

p sublevel = 3 orbitals (6 electrons)

d sublevel = 5 orbitals (10 electrons)

f sublevel = 7 orbitals (14 electrons)

C. Energy Levels, Sublevels, & Orbitals

ENERGY LEVELSSublevels (s, p, d, f)

Orbitals (1, 3, 5, 7)

Energy Level (n)

Sublevels # orbitals Max # e-

1 s 1 22 s

p13

2 6 (8 total)

3 spd

135

26

10 (18 total)4 s

pdf

1357

2610

14 (32 total)

III. Electron Configuration

A. Electron ConfigurationUnabbreviated method for describing the

arrangement of electronsExample: Helium (2 electrons)

Helium: 1s2

Energy LevelSublevel

# electrons

C. Energy Levels, Sublevels, & Orbitals

A. Electron ConfigurationExample: Neon (10 electrons)

Neon: 1s22s22p6

A. Electron ConfigurationExample:

Neon: 1s22s22p6

Tips to Remembering Electron ConfigurationSimply count, left to right, and know where s, p,

d, and f block are on the periodic table

B. Noble Gas ConfigurationAbbreviated electron configurationWrite full electron configuration for both Neon

(Ne) and Argon (Ar)Neon: 1s22s22p6

Argon:1s22s22p63s23p6

Argon: [Ne] 3s23p6