Chemical Notation

coefficient

superscript

subscript

No number means 1

species

total charge on the species

how many of that element in the species

how many of this species present

this element or compound

H3

O

+2

Examples

three iodide ions

one tri-iodide ion

these atoms are not bonded to each other

three iodine atoms bonded to each other

3I-

I3-

I-

I-

I-

I3-