Choose all descriptions that are true for chemical changes. (2)

Question

A. cutting down a tree is an example of a chemical change.
B. the chemical and physical properties change during a chemical reaction.
C. there are the same number of atoms before and after the change.
D. the identity of the substance stays the same.

Answer 1

The true descriptions for chemical changes are:

B. the chemical and physical properties change during a chemical reaction. C. there are the same number of atoms before and after the change.

Therefore, the correct choices are B and C.

A is false because cutting down a tree is a physical change, not a chemical one. D is also false because the identity of the substance changes during a chemical change.