Chemical equations must be balanced because

Answer 1

Chemical equations must be balanced because of the principle of the conservation of mass. This principle states that matter cannot be created or destroyed in a chemical reaction; therefore, the total mass of the reactants must equal the total mass of the products. Balancing a chemical equation ensures that the number of atoms of each element is the same on both sides of the equation, reflecting that mass is conserved during the reaction.

In summary, balancing chemical equations allows us to accurately represent the quantities of substances involved in a reaction and fulfills the fundamental law of nature regarding the conservation of mass.

Answer 2

mass can neither be created nor destroyed.
the mass of the products is always greater than the mass of the reactants. mass is determined by a chemical reaction.
the mass of the reactants is always greater than he mass of the products.

Answer 3

The correct statement regarding mass in chemical reactions is:

"Mass can neither be created nor destroyed."

This principle, known as the law of conservation of mass, asserts that in a chemical reaction, the total mass of the reactants must equal the total mass of the products. Therefore, the mass of the reactants is always equal to the mass of the products, not greater or less in any instance.

The other statements you provided are incorrect:

• "The mass of the products is always greater than the mass of the reactants." (False; they are equal.)
• "Mass is determined by a chemical reaction." (This is vague; chemical reactions transform substances but do not change the total mass.)
• "The mass of the reactants is always greater than the mass of the products." (False; they are equal.)

In summary, the principle of conservation of mass is the key concept in understanding chemical reactions.