Question

part b
which student explanation is best supported by the evidence from all four trials?
the appearance of the products changed, which caused the mass to change.
energy released during the reactions reduced the total mass of the products.
the number of product molecules was greater than the number of reactant molecules, which explains the results.
the atoms in the reactants were rearranged into new substances, but the total number of atoms stayed the same.

Explanation:

According to the law of conservation of mass in chemical reactions, atoms are neither created nor destroyed. They are just rearranged from reactants to products while the total number of atoms remains constant. Appearance change does not cause mass change, energy - mass relationship in normal chemical reactions is not relevant here as mass is conserved in normal chemical processes, and the number of molecules doesn't determine mass conservation.

Answer:

The atoms in the reactants were rearranged into new substances, but the total number of atoms stayed the same.