10. How are substances formed during a chemical reaction? A. New atoms come in an make new substances.

B. Substances aren't formed during chemical reactions.

C. The atoms of the reactions separate and regroup to form new a new substance(s).

D. The two substances stick together making a new substance.

Chemical reactions happen when chemical bonds are broken and formed. If the molecules in a substance bump into each other with enough energy, some of the bonds in the molecules can break. The atoms can form new bonds with different atoms. A new substance forms.

Explanation:

1. they vary with a higher number because boiling is way hotter than melting