The chemical formula for strontium hydride is written as SrH2. The symbol Sr represents the element strontium, and the symbol H represents the element hydrogen. The symbols for each element can be located on the periodic table of elements, which also lists their atomic number and their atomic weight.
The figure after the hydrogen symbol indicates that the formula contains two atoms of hydrogen. Since the strontium symbol isn't modified by a number, each molecule of strontium hydride contains only one atom of strontium. The number of atoms in a formula is generally written in subscript. The number of charges in a formula is written in superscript.