Journal/Discussion: (you will need your periodic table today!)

1. What are the four quantum numbers and what do they represent?

2. What do s, p, d and f stand for when we are talking about electrons?

3. How many electrons do the following elements have: C, W, Sc?

4. How is the maximum (or valence) energy level represented on the periodic table?

Spin Q.N.[spin of e-]

(ms)

Magnetic Q.N.[Orientation, orbitals]

(mL)

Angular Momentum QN[shape, sublevels, s p d f]

( L )

54

Principle Q.N.[Energy levels]

( n )

Qu

antu

m N

um

ber

s

Electron Configurations

The arrangement of electrons in atoms

Aufbau (building up) Principle An electron occupies the lowest energy

orbital that can receive it (aufbau principle)

Do not try to draw this diagram

Aufbau Principle

following the Aufbau Principle

Maximum number of electronss = 2 (only 1 orbital /sublevel)p = 6 (3 orbitals / sublevel)d = 10 (5 orbitals / sublevel)f = 14 (7 orbitals / sublevel)

Periodic Table – Filling Order – Aufbau Principle

1

2 13 14 15 16 17

18

Methods of Showing Electron Configuration

Electron Configuration Notation

Orbital Notation

Kernel Notation (Noble Gas) Configuration

Electron Dot Notation

Pauli Exclusion Principle

No two electrons in an atom have the same set of four quantum numbers. Electrons must have opposite spins

Hund’s Rule Orbitals of equal energy are each occupied

by one electron before any orbital is occupied by a second electron, and all electrons in singularly occupied orbitals must have the same spin

Method to show Electron Configuration Orbital Notation

He =

Phosphorus

Write the orbital notation for: Carbon (C) #6

Oxygen (O) #8

Scandium (Sc) #21

How to write an Electron Configuration?•The first number is the energy level. (1,2,3,4,5…)

•The lowercase letter is the sub-level. The sub-levels are named s, p, d and f. The number of available sub-level increases as the energy level increases.

•The number in superscript is the number of electrons in a sub-level.•Each sub-level can hold only a certain number of electrons. The s sub-level can hold no more than 2 electrons, the p sub-level can hold 6, the d sub-level can hold 10 and the f sub-level can hold as many as 14.

Method to show Electron Configuration

Electron Configuration Notation He = 1s2

P = 1s2 2s2 2p6 3s2 3p3

Write the electron configuration notation for: Carbon (C) #6

Oxygen (O) #8

Scandium (Sc) #21

Kernel Notation

Uses the noble gas (group 18) before the element and then shows the electron configuration notation for everything past the noble gas

P = [Ne] 3s23p3

Write the Kernel notation for: Carbon (C) #6

Oxygen (O) #8

Scandium (Sc) #21

Now do worksheet #1 Stay tuned… Later this week… Lewis Dot Structures

Lewis Dot Structure

Shows only the valence (outer) electrons Electrons in the outermost (highest) M.E.L. Only for main group (s and p block) elements Dots represent the electrons One on each side (starting at the top and

moving clockwise) then double them up Phosphorus