The answer from this questions is the letter
B. He should not use his opinions as evidence.
Answer:
KNO2, KBr
Explanation:
Chemical compounds are any substance composed of identical molecules consisting of atoms of two or more chemical elements. So NO2 and KBr are compounds, Br2 and Fe are not.
Answer:
1. B
2. D. the form of a substance changes but not its identity
3. C
4. D