The law which this student is thinking of is the law of conservation of mass (LOCOM).
What is LOCOM?
LOCOM is an abbreviation for the law of conservation of mass and it states that mass is neither created nor destroyed in any chemical reaction.
This ultimately implies that, the mass of any substance in a balanced chemical equation or chemical reaction would remain the same at the end.
According to the law of conservation of mass (LOCOM), the mass of all the reacting chemical elements of any substance must be equal (remain the same) to the mass of the product formed during a chemical reaction.
Read more on LOCOM here: https://brainly.com/question/24783543
