C) Tc-99 is a radioactive isotope also known as radioisoptope.
A, B and D should be the ones you should check
Intermolecular force for solids is high. Whereas low in gases. The smell of agarbatti spreads immediately because the molecules of air diffuses very fastly.
The rate of dissolution of a solid solute into the solution decreases when you stop stirring it. Generally, stirring increases the dissolution rate of a solid into a solution. An example is coffee with sugar, the sugar dissolves faster when stirred versus when left to dissolve on its own.
