What name is given to each of the following? The (a) irregular random movement of smoke particles in air. (b) existence of an element in various forms in th...

What name is given to each of the following? The

(a) irregular random movement of smoke particles in air.

(b) existence of an element in various forms in the same physical-state

(c) disintegration of atomic nuclei, accompanied with radiation emission.

(d) conversion of a solid difitrunto vapour without melting.