Elements and Compounds

Elements and
Compounds
Sodium (soft, silvery metal)
Fluorine (yellow-green gas)
Sodium Fluoride (colorless,
crystalline solid)
Hydrogen (clear gas)
Oxygen (clear gas)
Water (H2O) (liquid)
Elements

Single, unique atom

Have abbreviations called symbols

All element symbols contain ONE (1) capital letter
and sometimes a lower case letter as well

Examples
Compounds

2 or more different elements that are chemically
bonded together

Chemical bond = force of attraction that holds two
or more atoms together

Chemical bonds can be written in words or with
symbols

A compound symbol is called a chemical formula

Examples
Formulas

Identifies the number and types of atoms in a molecule
Glucose = C6H12O6
6C6H12O6
Coefficient
Subscripts
The prefix sub- means “below”
Formulas
6C6H12O6
LETTERS = Elements in the compound = element symbols
C = Carbon
H = Hydrogen
O = Oxygen
Formulas - SUBSCRIPTS
6C6H12O6
SUBSCRIPTS = # of atoms of each element
Carbon = 6
Hydrogen = 12
Oxygen = 6
Formulas - COEFFICIENTS
6C6H12O6
COEFFICIENT= # of molecules you have in all
Glucose molecule = 6
Total C atoms  6 atoms x 6 molecules = 36
Total H atoms  12 atoms x 6 molecules = 72
Total O atoms  6 atoms x 6 molecules = 36