Question

which statement correctly explains why the ashes of burnt paper have less mass than the original paper? (1 point)
the ash is created from new atoms that have less mass than the paper.
some of the atoms in the paper became gases.
some of the atoms in the paper are destroyed when it burns.
other atoms combine with the paper to produce the ash.

Explanation:

According to the law of conservation of mass, atoms are not created or destroyed in a chemical reaction. When paper burns, it undergoes a chemical reaction (combustion). Some of the atoms in the paper react with oxygen in the air to form gaseous products (such as carbon dioxide and water vapor). These gases escape into the atmosphere. The ash is the remaining solid residue. Since some of the atoms (in the form of gases) are no longer part of the solid mass (ash), the mass of the ash is less than the mass of the original paper.

• Option A is incorrect because atoms are not created in a chemical reaction.
• Option C is incorrect because atoms are not destroyed in a chemical reaction (law of conservation of mass).
• Option D is incorrect because if other atoms combined with the paper, the mass of the ash would likely be greater (not considering gas escape), and this option does not account for the gas formation and escape which is the main reason for the mass difference.

Answer:

B. Some of the atoms in the paper became gases.