Name_______________________________Period__________Date__________
Naming Binary Covalent Compounds
Binary covalent compounds come from the combination of two nonmetals (or a nonmetal and a metalloid). These
compounds do not involve ions; as a result, they have a slightly different naming system. Chemists use prefixes to
indicate the number of atoms in each compound.
Number
Greek Prefix (Memorize)
1
2
3
4
5
6
7
8
9
10
11
12
When naming binary covalent compounds, the first element name is given followed by
the second element with an “ide” ending. The first element gets a prefix when there is
more than one atom in the compound (NO mono on first element listed*). The second element ALWAYS gets a
prefix.
Binary Covalent Compound Name
Binary Covalent Compound Formula
*Nitrogen Monoxide
N2O
*NO2
Dinitrogen Trioxide
Dinitrogen Tetraoxide
N2O5
Prefixes are necessary when naming covalent compounds because the atoms can combine in any whole number
ratio. N2O, for example, cannot simply be called “nitrogen oxide,” because there are several other compounds that
contain nitrogen and oxygen. We must specify that there are two nitrogen atoms bonded to a single oxygen atom.
When dealing with ionic compounds, there is only one way for a cation and anion to combine to form a neutral
compound. As a result, there is no need to use prefixes. This is why CaCl2 is called “calcium chloride,” rather than
“calcium dichloride.”
Ionic Compound Name (NO GREEK)
Ionic Compound Formula
Lithium nitride
Lithium oxide
Barium fluoride
Barium phosphide
Compare and contrast the naming rules for Binary Ionic and Binary Covalent compounds. Record below:
Write the formulas for the following covalent compounds
1. antimony tribromide ______________________________
2. chlorine dioxide _________________________________
3. iodine pentafluoride ______________________________
4. ammonia ______________________________________
5. phosphorus triiodide ______________________________
Write the names for the following covalent compounds:
6. SeF6 _________________________________
7. Si2Br6 ________________________________
8. SCl4 _________________________________
9. CH4 _________________________________
10. NF3 ________________________________