Amixture in which the particles are to small to b seen with the naked eye is?

When the particles of a solution or a mixture are so small that they cannot be seen directly from our naked eyes the mixture was formed due called colloid. These are heterogeneous mixtures.

Explanation:

There are different methods to tell a mixture from compound and in this case it is done by passing light through it. When a beam of light is passed through this mixture the particles although being small all are enough such that scattering of the beam takes place and its path can be seen.  

b) nuclear ive learned that in a pedtrodic table