Questions

We know that All compounds are molecules, but not all molecules are compounds.

Water is a molecule because it is made from atoms that have been chemically combined. It is also a compound because the atoms that make water are not all the same - some are oxygen and some are hydrogen.

Hence, Water is a molecule and a compound.

In a chemical reaction, substances (elements or compounds) called reactants are changed into other substances (compounds or elements) called products. Hence, reactants are those which start the chemical reaction.

For example:

1. In the burning of natural gas, methane (CH4) and oxygen (O2) are the reactants in the chemical reaction. are the substances formed by a chemical reaction. In the burning of natural gas, carbon dioxide (CO2) and water (H2O) are the products formed by the reaction.

2. H2+O2 ----> H2O

Here H2 & O2 are called Reactants and H2O is called Product.