Question

In which state do molecules have the highest kinetic energy? in the liquid state in the solid state in the gaseous state during the phase change from liquid to gas

Answer 1

Answer: Option (c) is the correct answer.

Explanation:

Kinetic energy is defined as the energy obtained by an object or substance due to their motion.

Also, kinetic energy is directly related to temperature as follows.

                        K. E = $\frac{3}{2}kT$

Hence, kinetic energy is directly proportional to temperature.

So, more is the temperature provided to a substance more will be the kinetic energy of its molecules. Therefore, more will be their motion and this leads to more number of collisions between the molecules.

As in solids, molecules are held by strong intermoleculear forces so, they do not move from their initial position and hence, they have definite shape and volume.

In liquids, molecules are held by less strong intermolecular forces of attraction. So, they have definite volume but no definite shape.

In gases, molecules are held by weak intermolecular forces. So, these molecules are away from each other due to high kinetic energy as they have more number of collisions.

Thus, we can conclude that in the gaseous state molecules have the highest kinetic energy.

Answer 2

It depends on the substance,but for most substance it is in the gaseous state.