Electronic configuration

What is an orbital?

A space around the nucleus that a pair of electrons in likely to be in

What is electron spin-pair repulsion? (2)

Electrons can spin either clockwise or anticlockwise direction from around their own axis

Electrons with the same spin repel eachother

Quantum shell

A group of atomic orbitals that have the same principal quantum number, n

Spin-pairing

Two electron occupying the same orbital, but having opposite spins

Sub-shell

A group of orbitals within a quantum shell with the same energy level and a similar shape

Ground state (2)

The lowest possible energy level of an electron

It is the shell closest to the nucleus

Emission spectra

Electromagnetic radiation emitted by an atom or molecule when an electron transitions from a higher energy level to a lower one

How to write electron configurations (3)

Electrons fill up the lowest energy subshells first

Electrons fill orbitals with with 1 electron before pairing up

To form an ion, add or remove electrons from the highest energy subshell

What does 2s² mean? (3)

Large 2 = Principle quantum number (electron shell)

S = subshell (s,p,d,f)

Small 2 = number of electrons

How many electrons on 1 orbital?

2

What are the maximum number of electrons on each subshell? (4)

s = 2 (1 orbital)

p = 6 (3 orbitals)

d = 10 (5 orbitals)

f = 14 (7 orbitals)

What is a shorthand way to write electron configuration?

Start with the noble gas from the previous period eg. Beryllium = [He] 2s²

Emission spectra for hydrogen (4)

A hydrogen molecule is broken into hydrogen atoms

The electron in a hydrogen atom absorbs energy and gets excited

The electron jumps from a lower energy level to a higher energy level

When it comes back to its original state, it emits electrogmagnetic radiation which forms a hydrogen spectrum

What is the s-block?

Group 1-2

What is the d-block

The transition metals

What is the p-block?

Non-metals (Groups 3-8)

What is the f-block?

The lanthanide series and the actinide series

What is the electronic configuration of chromium?

1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹

What is the electronic configuration of copper?

1s²2s²2p⁶3s²3p⁶4s²3d⁹

What happens when transition metals form ions?

The electrons are removed from the 4s subshell before the 3d subshell