Question

What happens to some metals when the kinetic energy of their particles is decreased?

Answer 1

Decreasing the kinetic energy of metal particles can lower the metal's temperature, potentially leading to a phase change, and affect its electrical resistance and reaction rates due to a reduction in particle collisions and activation energy.

Step-by-step explanation:

When the kinetic energy of particles in a metal is decreased, the metal undergoes various changes, most notably a decrease in temperature. As metals cool, their atoms and electrons have less energy to move, potentially leading to a phase change, such as solidification if the metal was previously in a liquid state. Additionally, decreasing the kinetic energy can affect the metal's electrical resistance; as the particles slow down, they collide less, which could decrease the resistance.

The photoelectric effect is another phenomenon associated with changes in kinetic energy in metals. When metals are exposed to light above a certain threshold frequency, they emit electrons. If light with a frequency below that threshold is used, or the kinetic energy of the particles in the metal is decreased, no electrons would be ejected.

Answer 2

less heat energy is supplied to the atoms

Step-by-step explanation:

When we decrease the temperature, less heat energy is supplied to the atoms, and so their average kinetic energy decreases. When they enter a phase transition, such as freezing from a liquid to a solid, the temperature is not decreasing or increasing, and stays constant.