Consider a colloidal suspension(like a solution) of very small particles in a solvent. We may think of this as an ideal gas of particles in the external field due to gravity. The potential energy of a single particle is then U(z)=zmg, where z is the height of the particle, m is its mass, and g is the gravitational constant.
The number of particles N(z) at a given height z is proportional to e^(-ßzmg). Explain why this is reasonable