Question

practice lesson 2: changes in matter complete the following three exercises. 1. explain the law of conservation of mass with an example.

Explanation:

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. For example, when hydrogen gas ($H_2$) burns in oxygen gas ($O_2$) to form water ($H_2O$), the total mass of the reactants (hydrogen and oxygen) is equal to the total mass of the product (water). If 4 grams of hydrogen react with 32 grams of oxygen, 36 grams of water are formed. The number of atoms of hydrogen and oxygen remains the same before and after the reaction, just rearranged into a different compound.

Answer:

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. For example, when hydrogen gas burns in oxygen gas to form water, the total mass of hydrogen and oxygen (reactants) equals the total mass of water (product). If 4 grams of hydrogen react with 32 grams of oxygen, 36 grams of water are formed.