atomic structure

Question 1

Shells, sub shells and orbitals

Answer 1

Electrons are arranged in electron shells(energy levels)
the shells have sub shells(sub levels)
each shell/subshell is made up of orbitals each can hold 2 electrons

Question 2

sub levels in order of energy

Answer 2

1s (2)
2s (2)
2p (6)
3s (2)
3p (6)
4s (2)
3d (10)
4p (6)
5s (2) 
4d (10)
5p (6)
4f (14)

Question 3

Aufbau principle

Answer 3

electrons enter the lowest energy orbital available

Question 4

Hund’s rule

Answer 4

Electrons prefer to occupy orbitals on their own and only pair up when no empty orbitals of the same energy are available

Question 5

exceptions

Answer 5

Cr= 1s2 2s2 2p6 3s2 3p6 4s1 3d5

Cu= 1s2 2s2 2p6 3s2 3p6 4s1 3d10