Question

explain how the total mass of a substance remain unchanged during chemical change​.

Answer 1

Answer:

take a paper and weight it and note the weight of the paper and then burn the paper and weight the ash it would be same as of the paper

Answer 2

Answer:

Atoms are not created or destroyed in a chemical reaction, they are just rearranged from the reactants to form the products. ... If a chemical reaction is completed in a closed system (when nothing extra can get in and nothing can escape), then the mass will remain constant.