What do we call the substances that are present before a reaction takes place?

1. A chemical equation is written with an arrow pointing from left to right. 2. The substances written before the arrow are there at the start. 3. Those starting substances are called the reactants. 4. The substances made by the reaction are called the products. _Source: Siyavula Natural Sciences Grade 8 (CC BY 4.0), Reactants and products_