In a chemical equation, a reactant is a substance that is consumed during the chemical reaction. They are the starting materials of the reaction, and they are written on the left-hand side of the chemical equation.

Here's a simple analogy:

Imagine baking a cake. The reactants are the flour, sugar, eggs, butter, and other ingredients you mix together. The product is the delicious cake you get after baking.

Similarly, in a chemical reaction:

* Reactants are like the ingredients you combine.

* Products are like the new substance(s) formed.

Here are some important points about reactants:

* Reactants undergo chemical changes during the reaction.

* Their chemical bonds break and form new bonds, resulting in the formation of products.

* The amounts of reactants determine the amount of products formed (according to the stoichiometry of the reaction).

Example:

The reaction of hydrogen gas and oxygen gas to form water:

2 H₂(g) + O₂(g) → 2 H₂O(l)

In this equation:

* H₂(g) and O₂(g) are the reactants (hydrogen gas and oxygen gas).

* H₂O(l) is the product (liquid water).

Let me know if you have any other questions!