Answer:
Those are several statements to choose which are true. You must select all that apply.
All but the third one are true. The true statements are:
- There are gas molecules that move slower than the average.
- The average speed of gas molecules increases with increasing temperature.
- There are gas molecules that move faster than the average.
- The average kinetic energy of gas molecules increases with increasing temperature.
The stament that is false is:
- All the gas molecules in a sample have the same kinetic energy.
Step-by-step explanation:
According to the kinetic molecular theory, a gas sample consists on a group of particles (molecules or atoms) which are in constant random motion, and the average kinetic energy of such gas particles depends on the temperature of the gas and nothing else.
The average kinetic energy increases when the temperature of the gas increases (this tells that the fifth statement is true).
At any time, some gas particles will be moving faster than others, but the gas can be described by an average kinetic energy.
Since it is the average kinetic energy what characterizes a sample of gas, not all the gas molecules in a sample have the same kinetic energy, some molecules move faster and other slower. With that you deal with these statements:
- First: There are gas molecules that move slower than the average. TRUE.
- Third: All the gas molecules in a sample have the same kinetic energy. FALSE.
- Fourth: There are gas molecules that move faster than the average. TRUE.
The second statement, that the average speed of gas molecules increases with increasing temperature, is derived from the fact that the kinetic energy is directly related to the square of the speed:
- Kinetic energy = (1/2) mass × speed²
So, if the average kinetic energy increases with the temperature, the average speed too.