Explain why a chlorinated swimming pool water would be a homogenous mixture?

A chlorinated swimming pool would be a homogenous mixture because chlorine and water diffuse through each other and cannot be separated out as distinct materials. They homogenously mix and appear as one and cannot be divided into their pure forms. 

Explanation:

Homogeneous mixtures look an equivalent throughout. A pool may be a solid mixture as a result of it's water and chlorine and you cannot visually tell them apart. The example of a heterogeneous mixture would really like sand or water mixed with oil.

found in the nucleus

has mass of one amu