Chapter 7 7-1 symbol? an abbreviation for the name of the element Chemical formula? a type of notation made with numbers and chem. Symbols To indicate the composition of a compound To indicate the number of atoms in one molecule of an element molecule? a single atom, a group of 2+ atoms of the same element, or a group of atoms of different elements that have combined to form a compound Monoatomic molecules? molecules with one atom Diatomic molecules? two atom molecules Hydrogen, oxygen, nitrogen, chlorine, fluorine, bromine, Iodine When writing the formula for a molecule of an element, write the number of atoms in each molecule as a subscript just after the symbol The formula of a compound tells 2 things: The element making up the compound