Lithium has 3 protons and three electrons in its neutral state. In a higher energy state, it loses its outer electron to become Li+ or ionized lithium.
Lithium is in group 1 on the Periodic Table. This means that it has only 1 valence electron. Lithium will tend to lose that electron when it ionizes and become an ion. An ion is any atom or molecule with a charge. When Li loses the electron, it loses one of its negative charges so the atom becomes an ion with a +1 charge because it now has 3 positively charged protons and only 2 negatively charged electrons.
Lithium is a cation because it has a positive charge. It loses one electron to achieve stability and form the Li+ ion.
Cation because it gives away its valence electrons in order to form an Ionic Compound, ie. LiCl
Silver is normally not a cation or an anion, it is an element. Once it becomes an ion however, it will become a CATION with a +1 charge (Ag^+).
The cation of lithium is Li+.
anion