Remember Covalent Compounds  Composed of two or more nonmetals.  Usually gases or liquids at room temperature.  Non-electrolytes: do not conduct electricity when dissolved in water

Rule 1  The most “metallic” element is written first. This is the least electronegative element.  Exception: when the compound contains oxygen and a halogen, the name of the halogen is the first word in the name.

Rule 2  The second element in the name is named as if it was an anion, by adding the suffix -ide to the name of the element.  The first elements name stays the same

Rule 3  Greek prefixes are used to indicate the number of atoms of each nonmetal element present.  The prefix mono is only used for oxygen

Greek Prefixes You use most of these regularly. For example: You use most of these regularly. For example: What do you call a train that runs on one rail? What do you call a train that runs on one rail?

MONORAIL

A choice between two options is a …

dilemma

What do you call the non-motorized object that has pedals and 3 wheels? What do you call the non-motorized object that has pedals and 3 wheels?

Tricycle Tricycle

How many blocks in each tetris piece?

Tetra = 4

What is the name of the 5 sided building in Washington DC?

pentagon

What are these?  HEX nuts  Hexa = 6

hepta

octa

nona

deca

Greek Prefixes Here is an example of how we use the prefixes with the elements to name compounds.

Some important exceptions to remember  All diatomic (gen-u-ine) elements are just named for their element  Ex: O 2 = oxygen  Other exceptions are methane CH 4 and ammonia NH 3  And carbon and hydrogen compounds

Practice Example #1: N 2 O 4 :_________________ Example #2: SF 6 :___________________ Example #3: diphosphorus pentoxide:______ Example #4: phosphorus pentachloride :_______ Dinitrogen tetraoxide