Ionic Bonds

Ion – atom or group of atoms that has an electric charge

Ionic bonds form when atoms gain or lose electrons.

When an atom loses an electron, it becomes a positive ion. Ex. Li+

When an atom gains an electron, it becomes a negative ion. Ex. Cl-

How Ions Form

A compound that consists of ions is called an ionic compound.

The name of the positive ion comes first, followed by the name of the negative ion. (This means metal before nonmetal or metalloid, left before right)

A chemical formula is a combination of symbols that shows the ratio of elements in a compound. Ex. CO = 1 carbon & 1 oxygen

A subscript tells you the ratio of elements in the compound. Ex. CO2 (2 = the subscript)

If there is no subscript (number), the number is understood to be 1.

Chemical Formulas

The magic number is 2 and 8. All atoms will lose, gain, or share

electrons to get to the magic number. Ionic bonds generally occur between

metals and nonmetals (or different sides of the periodic table).

Example: Cl has 7 electronsH has 1 electronHCl has 8 so the two

combine

Reminders