When a rock falls from outer space all the way to the groung, its called a?

a  solution  is always transparent, light passes through with no scattering from solute particles which are molecule in size. the  solution  is homogeneous and does not settle out. a colloid is intermediate between asolution  and a  suspension. while asuspension  will separate out a colloid will not.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.