Which of these changes is an example of a chemical change?
A. sodium making an explosion when added to water
B. solid CO₂ turning into gaseous CO₂
C. water droplets forming outside a glass on a hot day
D. evaporation of water from a pan
Answer (1)
The explosion of sodium when added to water is an example of a chemical change, as it produces new substances. In contrast, the other examples—solid CO₂ sublimating, water droplets forming through condensation, and water evaporating—are all physical changes. Thus, the correct answer is sodium's reaction with water. ;
