A substance has a higher temperature when its particles have a higher average kinetic energy.

Question

Imagine two different substances that are both pure, meaning they each contain only one type of matter. Each substance has a different temperature.
Which two properties determine which substance has the higher temperature?
A. The mass of each substance
B. The mass of one particle in each substance
C. The kinetic energy of the fastest particle in each substance
D. the average speed of the particles in each substance

Answer 1

The two properties that determine which substance has the higher temperature are:

B. The mass of one particle in each substance: This can influence the average kinetic energy of the particles. However, it is more relevant in the context of comparing the average kinetic energy relative to their masses.

D. The average speed of the particles in each substance: The average speed of the particles is directly related to their kinetic energy. The temperature of a substance is proportional to the average kinetic energy of its particles, which can depend on their average speed.

While options A and C provide context, they do not directly determine temperature in the way the question specifies. The average speed (D) is particularly crucial in defining the average kinetic energy, which, in turn, defines temperature. Thus, the best answer focuses mainly on average speed (D), potentially considering the mass of particles as a secondary factor (B), though average speed generally has a more direct relationship with temperature.