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?
Answer
A
A chemical reaction occurs because the liquid becomes cloudy.
B
A physical change occurs because the metal gets smaller.
C
A chemical reaction occurs because heat and light are given off.
D
A physical change occurs because vapor is released into the air.
Explanation
The orange flame shows that energy is being released as heat and light, which is evidence of a chemical reaction. Sodium reacts with water to form new substances, including hydrogen gas. Thus, the best conclusion is that a chemical reaction occurs because heat and light are given off.
AI-written and checked against the verified answer.