Periodic Trends

Ionization energy- qualitatively defined as the amount of energy required to remove the most loosely bound electron of an isolated gaseous atom to form a cation

Electron affinity- neutral atom's likelihood of gaining an electron

Atomic radius- total distance from an atom’s nucleus to the outermost orbital of electron

Periodic trends all follow a set pattern with a few exceptions. Electron affinity and ionization energy both go up and to the right, while atomic radius goes down and to the left.

Resources:
Electron Affinity
Electron Affinity Khan Academy
Ionization Energy
Atomic Radius