StellarCations
Cations are positively charged ions that are formed when an atom loses electrons. This usually happens to metals, since they have a low amount of valence electrons and have lower ionization energies. The alkali metals in group one have only one valence electron, so they lose that electron and gain a +1 charge. Alkaline earth metals in group 2 have two valence electrons, so they lose two electrons and gain a +2 charge. Elements in group 13 have three valence electrons, so they lose three electrons and gain a +3 change. Transition metals in groups 3-12 also become cations, and they lose varying amounts of electrons.