Water does not wet an oily glass because

On wearing a rain coat on which some greasy material is coated, a person does not wet in rain because-

A mercury drop does not spread on a glass plate because the angle of contact between glass and mercury is

If a glass rod is dipped in mercury and withdrawn out, the mercury does not wet the rod because

Mercury does not wet glass, wood or iron because

Mercury does not wet the glass. Why?

A mercury drop does not wet glass whereas a water drop sticks to glass. Why?