It's a cyclohexane ring with an ethyl group at 1 and a methyl group at 3. The Ethyl group is bigger and more important group get's the first position.
1-ethyl-3-methylcyclohexane
Answer:
C. Atom 3
Explanation:
I'm sorry if I answered this late, but hope this helps! :D
I think it's physical change
The greenhouse effect captures the sun's energy and keeps the earth warm.