Question

When sodium metal is added to water, an orange flame is observed on the metal surface. Based on this observation, what can best be concluded?

A physical change occurs because the metal gets smaller.
A chemical reaction occurs because the liquid becomes cloudy.
A chemical reaction occurs because heat and light are given off.
A physical change occurs because vapor is released into the air.

Answer 1

I think the 3rd one

Answer 2

Thanks!