Two ways of writing e-configs. One is called spectroscopic notation. Other is called the orbital box notation. Electron affinity Atomic Size Size goes UP going down a group. Electrons are added further from the nucleus, there is less attraction.
Size goes DOWN going across a period.
Trends in ion sizes are the same as atom sizes. This is why ox. Metals lose electrons more easily than nonmetals. Metals are good reducing agents. Nonmetals do not lose electrons.