Question 21: Classification of Changes
- Liquid water boiling and becoming steam: b. Physical Change
- Silver metal tarnishing and becoming silver sulfide: a. Chemical Change
- Paper burning: a. Chemical Change
- Bending copper wire: b. Physical Change
- Dissolving salt in water: b. Physical Change
- Iron rusting to become iron oxide: a. Chemical Change
Question 22: Effect of Heating a Scuba Tank
The correct answer is: b. The pressure exerted by the gas in the tank would increase.
When the temperature of the gas increases, the kinetic energy of the gas particles increases, leading to an increase in pressure, as long as the volume remains constant.
Question 23: Difference Between Vector and Scalar
The correct answer is: a. A vector measurement contains a direction and magnitude, a scalar measurement only contains a magnitude.
Vectors have both magnitude and direction (e.g., velocity, force), while scalars have only magnitude (e.g., temperature, mass).