Question

the particles in gas a and gas b are moving at the same average speed. each particle in gas a has more mass than each particle in gas b. in which gas do the particles have the higher average kinetic energy? gas a gas b neither; their particles have the same average kinetic energy which has the higher gas pressure? gas a gas b neither; their gas pressures are the same

Explanation:

Step1: Recall kinetic - energy formula

The kinetic - energy formula is $K = \frac{1}{2}mv^{2}$, where $m$ is mass and $v$ is speed. Given that the average speed $v$ is the same for gas A and gas B, and $m_A>m_B$ (mass of particles in gas A is greater than that in gas B).

Step2: Compare kinetic energies

Since $K=\frac{1}{2}mv^{2}$ and $v$ is constant, when $m_A > m_B$, we have $K_A>K_B$. So, the particles in gas A have higher average kinetic energy.

Step3: Recall pressure - kinetic - theory relation

According to the kinetic - theory of gases, pressure $P$ is related to the average kinetic energy of the particles and the number of collisions with the walls of the container. Higher average kinetic energy means more forceful collisions. Since gas A has particles with higher average kinetic energy, gas A has higher pressure.

Answer:

In which gas do the particles have the higher average kinetic energy?
A. gas A
Which has the higher gas pressure?
A. gas A