ELECTRON CONFIGURATION

Question 1

Niels Bohr

Answer 1

-1913
- Electrons only exist when moving in spherical orbits at distances away from the nucleus
- Bohr orbits / shells

Question 2

Electron shells

Answer 2

N = principle quantum number
N 1 = first shell (2 e-)
N2 = second shell (8 e-)
N3 = third shell (18 e-)
N4 = fourth shell (32 e-)

Question 3

Subshells

Answer 3

S subshell = 2 e- (1 line)
P subshell = 6 e- (3 lines)
D subshell = 10 e- (5 lines)
F subshell = 14 e- (7 lines)

Question 4

Energy level organisation

Answer 4

1s
2s
2p
3s
3p
3d
4s
4p
4d
- ON ACTUAL EC DIAGRAM, 4S COMES BEFORE 3D BUT IS WRITTEN AFTER!

Question 5

Atomic orbitals and electrons

Answer 5

• each holds 2 e-
• e- spins clockwise or anticlockwise
• orbitals with same energy (spin up and down e-) called degenerate orbitals

Question 6

Why do electrons have opposite spins

Answer 6

To avoid inter electron repulsion.
This is the force between electrons due to their negative charges. The charges repel and e- are pushed away from eachother

Question 7

Atomic orbitals

Answer 7

This is a region around an atom where there is a high probability of finding an electron

Question 8

Heisenberg’s uncertainty principle

Answer 8

Says you can determine either the speed or position of an electron

Question 9

Boundary surface diagrams

Answer 9

Used to represent the shape of an orbital by indicating a surface containing a specific proportion of the electron density.

It visualises where electrons are found around a nucleus.
95% probability of finding an electron

Question 10

Shape of P orbitals

Answer 10

3 P orbitals
Dumb bell shaped
2 lobes with little electron density in the nucleuss

Question 11

Shape of D orbitals

Answer 11

5 D orbitals
Clover leaf shaped