Chemical Names and Chemical

Formulas

A chemical symbol is an abbreviation for the name of an element.

Example: Al – Aluminum

O – Oxygen

**Notice that a single-letter symbol is always capitalized and that the first letter of a two-letter symbol is always capitalized and the second letter is not.

A chemical formula is the combination of symbols that represents a particular compound.

A chemical formula indicates which elements are found in the compound, as well as the number of atoms of each element that are found in the compound.

Examples:

NaCl – 1 atom of Na – sodium

- 1 atom of Cl – chlorine

H2O – 2 atoms of H – hydrogen

- 1 atom of O - oxygen

Rules For Naming Ionic Compounds

 

1. Metals combine with nonmetals in many compounds.

2. Write the name of the metal first and the nonmetal second.

3. Change the ending of the nonmetal to “ide”.

Examples:

NaCl - Na (metal) – sodium

- Cl (non-metal) – chloride

Mg2O3 -Mg (metal) – magnesium

- O (non-metal) - oxide

Sodium chloride

Magnesium Oxide

Try These

Ca3P2 –

Li3N –

K2S –

Try These

Ca3P2 – Calcium phosphide

Li3N – Lithium nitride

K2S – Potassium sulfide

Rules For Writing The Formulas for Ionic Compounds

1. Metals combine with nonmetals in many compounds.

2. Each atom has its own combining capacity (charge/hooks).

3. Atoms combine so that each atoms combining capacity if full. Each atoms needs to be “balanced”.

4. When writing the formula the metal symbol is first and the nonmetal symbol is second.

5. The number of each kind of atom needs to be specified. (H2O)

Examples:

Beryllium chloride

Sodium nitride

In-class Assignment

Write the chemical formulas for the following ionic compounds. 

1. Silver (I) Iodide

2. Gold (III) Chloride

3. Tin Sulfide

4. Calcium Nitride

5. Sodium Bromide

6. Iron (III) Oxide

7. Lithium Fluoride

8. Magnesium Phosphide

9. Potassium Chloride

10.Lead Phosphide

Write the chemical name for the following ionic compounds.

 

1. CoSe

2. HgF2

3. Na3P

4. Ba3As2

5. CaBr2