Relative formula mass No atoms are created or destroyed during a chemical reaction. This allows calculations to be made on the quantities of substances that react and of the products made.

The relative formula mass close relative formula massThe sum of the relative atomic masses of the atoms in a chemical formula. of a substance made up of molecules close moleculeA collection of two ...

How dangerous a chemical can be also depends on how easily it can spread and contaminate the environment. The physicochemistry of a substance plays an important role here.