Quantum Mechanics

Bohr Theory

• The electron is a particle that must be in orbital in the atom

Quantum Theory

• The electron is the cloud of negative charge in a wave function
• Orbitals are areas in 3D space where the electrons most probably are
• The energy of the electrons is in it's vibrational nodes
• Photons are produced when high energy modes change into lower energy modes

Determining an elements chemical properties is it's electron configuration, particularly the valence shell electrons. The type of orbital the atom's outermost electrons reside determines the 'block' and the number of valence shell electrons determine the 'group'.

The total number of electron shells detemines the period it belongs and each shell is divided into sub-shells

Subshell:	S	G	F	D	P
Period
1	1s
2	2s				2p
3	3s				3p
4	4s			3d	4p
5	5s			4d	5p
6	6s		4f	5d	6p
7	7s		5f	6d	7p
8	8s	5g	6f	7d	8p

Through a group of lightest element to heaviest element, the outer shell electrons are all in the same orbital, with a very similar shape, but increasingly higher energy and distance from the nucleus. The outer shell, for instance, all have one electron in an s-orbital. In hydrogen, the s-orbital is the lowest possible energy state of any atom, the first.



 The different regions of the atomic table are named according to the sub-shell in which the last electron is...

S-Orbital
- Each Orbital holds two electrons
- Spherically symmetric around the nucleus
- Only has one orbital

P-Orbital
- There are 3 sub-orbitals
- Each Orbital contain 2 electrons
- In total, there are 6 electrons

D-Orbital
- There are 5 sub-orbitals
- Each orbital contains 2 electrons
- In total, there are 20 electrons

F-Orbital
- There are 7 sub-orbitals
- Each contain 2 electrons
-In total, there are 14 electrons

Here's a really helpful video to help understand electron configuration

Lets see if you can do some! (:

1. What is the electronic configuration for nickel?
2. What is the electronic configuration for Gold?
3 What is the electronic configuration for Zinc?

Answers
1. 1s2 2s2 2p6 3s2 3p6 3d8 4s2
2. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 4f14 5d10
3. 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰