What are the reactants

Reactants are initiators of a chemical reaction

Explanation:

In a chemical reaction, there are two types of substances involved: reactants and products.

The reactants are substances that are utilized to in a chemical reaction which undergo certain changes and thereby producing products at the end of a reaction

On can write chemical equation as :

A + B → AB

where A and B are reactants which underwent a reaction to produce the product AB.

For example

2 + → 2O

|______|        ↓

Reactants      Products

When writing a chemical equation, reactants are always written on left hand side of an arrow and the products on the right hand side.

conservation of mass

mass before something happens = mass afterwards