Ionic Bond

Chapter 5 Section 2

Ions

• •

Ion

- Is an atom or group of atoms that has an electric charge • When an atom loses an electron it becomes positively charged.

• When an atom gains an electron it becomes negatively charged.

Polyatomic ions

are ions that are made of more than one atom, and they have an overall positive or negative charge.

•

Ionic bonds

are formed as a result of attraction between positive and negative ions.

•

Ionic compounds

consists of positive and negative ions example: Sodium Chloride NaCl

Chemical Formulas and Names

• Ionic compounds are made up of a metal and a nonmetal • To write the formula of an ionic compound you must make sure the compound’s overall charge is zero. (listen to explanation).

• To name an ionic compound you should name the positive ion first followed by the name of the negative ion. Example: Magnesium Oxide. Notice the ending of negative ion it is always -

ide

Properties of Ionic Compounds

• 1. Hard, brittle solids • 2. Have high melting points • 3. They make a three dimensional pattern called crystal or crystal lattice.

• 4. Solutions of ionic compounds conduct electric current.