# How do you determine which atoms would have the greatest velocity if each atom had the same kinetic energy?

## For example, between hydrogen, bromine, chlorine, and ammonia?

##### 1 Answer
Sep 2, 2017

The kinetic energy of a molecule is,

$E = \frac{1}{2} m {v}^{2}$ where $v$ is the Molecular velocity and $m$ is the mass.

Thus, if a number of molecules have the same kinetic energy but different masses, the one with the least mass has the greatest velocity and the one with greatest mass moves with slowest velocity.

Thus, as mass increases, the velocity decreases for a given Kinetic energy.