Electron transfer is the term for this process. The resulting anion and cation are attracted by Coulombic forces and an ionic compound is formed. Ionic compounds are neutral: the number of electrons lost in forming the cation(s) must equal the number gained in forming the anion(s). For example, Aluminum (Al, Z = 13, Group 3A or 13) will lose 3 electrons to become Al3+ which is isoelectronic with Neon (Ne), its closest noble gas. To form an ionic compound those 3 electrons must be picked up by a nonmetal. Two possibilities are:

Nitrogen (N, Z = 7, Group 5A or 15) gains all 3 electrons to become isoelectronic with Neon (Z = 10). The compound formed is AlN

3 Chlorine atoms (Cl, Z = 17, Group 7A or 17) each gain 1 electron to become isoelectronic with Argon (Ar, Z = 18). The symbol for the compound formed is AlCl3. The subscript after Cl indicates that 3 Cl- anions are required.

(1 pt) Form an ionic compound with sodium (Na):

Its atomic number is:

How many electrons must it lose to have the same number of electrons as its nearest noble gas?

Write the symbol for the ion:

Which nonmetal atom needs to gain that same number of electrons to have the same number of electrons as its nearest noble gas?

Write the symbol for the compound formed:

(1 pt) Form an ionic compound with calcium (Ca):

Its atomic number is:

How many electrons must it lose to have the same number of electrons as its nearest noble gas?

Write the symbol for the ion:

Which nonmetal atom needs to gain that same number of electrons to have the same number of electrons as its nearest noble gas?

Write the symbol for the compound formed: