is the amount the energy required to move an electron from one energy level to another energy level.

is a subatomic particle, symbol e⁻ or β⁻ , whose electric charge is negative one elementary charge.

is a subatomic particle, symbol p, with a positive electric charge of +1e elementary charge and a mass slightly less than that of a neutron.

is a subatomic particle, symbol n, which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton.

is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei.

is spherically symmetric around the nucleus of the atom, like a hollow ball made of rather fluffy material with the nucleus at its centre.

is ​the region of negative charge surrounding an atomic nucleus that is associated with an atomic orbital.

s p d t

s k t f

s p b f

s p d f

8

2

18

32

118

2

50

96

1s2 2s2 2p6

1s3 2s9 2p2

1s2 2s2 2p4

1s2 2s2 2p6 3s2 3p4