Which substance has the highest particle mobility?

water at 25 °C because liquid particles are the most mobile and mobility increases with decreasing temperature
steam at 105 °C because gas particles are the most mobile and mobility increases with increasing temperature
nitrogen gas at -200 °C because gas particles are the most mobile and mobility increases with decreasing temperature
ethyl alcohol at 30 °C because liquid particles are the most mobile and mobility increases with increasing temperature

I think its b

It's b. Gas is the form that molecules are most mobile in. The colder it gets, the closer it is to being water/ice.

I agree with b.

To determine which substance has the highest particle mobility, we need to consider the state of matter and temperature.

Particle mobility refers to the ability of particles in a substance to move freely. In general, the mobility of particles increases with temperature, as the kinetic energy of particles increases, allowing them to move more rapidly.

Water at 25 °C is a liquid, and in liquids, particles have the ability to move, although they are more constrained compared to gas particles. However, the statement that "mobility increases with decreasing temperature" is incorrect. In fact, mobility usually increases with increasing temperature. Therefore, water at 25 °C does not have the highest particle mobility.

Steam at 105 °C is in the gaseous state, and gas particles are generally more mobile compared to liquid or solid particles due to their higher kinetic energy. The statement that "mobility increases with increasing temperature" is correct for gas particles. Therefore, steam at 105 °C has higher particle mobility compared to water at 25 °C.

Nitrogen gas at -200 °C is also in the gaseous state. While the temperature is much lower, gas particles still retain their mobility. However, the statement that "mobility increases with decreasing temperature" is incorrect for gas particles. As temperature decreases, the kinetic energy of gas particles decreases, leading to reduced particle mobility. Therefore, nitrogen gas at -200 °C does not have the highest particle mobility.

Ethyl alcohol at 30 °C is also a liquid, similar to water. The statement that "mobility increases with increasing temperature" is correct for liquid particles. Therefore, ethyl alcohol at 30 °C has higher particle mobility compared to water at 25 °C, but it is not as high as the particle mobility of steam at 105 °C.

In conclusion, the substance with the highest particle mobility is steam at 105 °C because gas particles are the most mobile, and mobility generally increases with increasing temperature.