The molecules which evaporate into the gas phase are the ones traveling with velocity.

Explanation:

In gases, the molecules are held by weak Vander waal forces. Hence, they have high kinetic energy due to which they tend to move rapidly from one place to another leading to more number of collisions.  

Therefore, when number of collisions increases then force applied by the molecules on each other also increases.

As a result, velocity of the particles increases.

Therefore, we can conclude that the molecules which evaporate into the gas phase are the ones traveling with high velocity.

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