what is always true according to the law of conversation of matter, new molecules cannot be formed from the reactants during a chemical reaction atoms created during a chemical reaction must have the same mass as the atoms in the reactants total number of molecules before and after chemical reaction says the same skin be right during a chemical reaction, but cannot be added or taken away

The statement that is always true according to the law of conservation of matter is that atoms created during a chemical reaction must have the same mass as the atoms in the reactants.