Question

According to the law of conservation of matter, the number of ________ is not changed by a chemical reaction.


molecules
bonds
atoms
products

Answer 1

According to the law of conservation of matter, the number of  Atoms is not changed by a chemical reaction. 


 They're the same before and after a chemical reaction

Answer 2

According to the law of conservation of matter, the number of atoms is not changed by a chemical reaction.