# Question #a8817

Symbol = element
Formula = compound

#### Explanation:

A chemical symbol is used to show an element which is not combined with any other elements. I'll list some examples.

H = hydrogen
He = helium
Li = lithium
N = nitrogen
Na = sodium

Notice that symbols can have 1 or 2 letters. The first letter is capitalized, the second must be written with a lowercase letter.

A chemical formula gives the type and number of elements which are found in a chemical compound. Here are some examples.

CO = carbon monoxide (carbon with oxygen)
${H}_{2} O$ = water (hydrogen with oxygen)
NaCl = sodium chloride/salt (sodium with chlorine)
${C}_{6} {H}_{12} {O}_{6}$ = glucose (carbon, hydrogen and oxygen)

Here are a couple videos to help with writing chemical formulas.

Hope this helps!