For coarse reduction of hard solids, use

The opening of 200 mesh screen (Taylor series) is

The ratio of the actual mesh dimension of Taylor series to that of the next smaller screen is

Air has 21 % oxygen and 79 % nitrogen by volume. What is the average molecular weight ? (Atomic weight of O = 16, N =14)

A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is

An ideal solution obeys