A chemical formula is a representation of the smallest unit of a compound using elemental symbols to show the types of elements in the unit. Subscripts in the chemical formula are numbers written below and to the right of chemical symbols, showing the number of a specific type of atom present. If there is no subscript, only one atom of that element is represented in that
compound. Using the chemical formula models on this page, write the formulas and the elements in each of the following three compounds as well as the number of atoms in each in
parentheses
Water: