b) in a gas there are no bonds between particles so nothing keeps them together. The bonds in a solid are strong so it dissolves slowly. However the liquid is viscous (elastic and weak bonds, unlike gas which has no interparticle bonds) so the difussion processes is slower in liquids than in gasses. Alternatively, the liquid has greater density (particles per unit of volume) than gas, so moving among/between particles is harder in a liquid (more stuff to move around) than in a gas (less stuff to move around)

c) evaporation, and evaporation is a cooling process – it requires heat (energy) to get a particle energetic enough to leave a liquid and cross the liquid – air boundary. The hotter the liquid, the more energy that is available to a particle to cross this boundary. Think of bouncing balls in an arena – with more energy the ball (particle) can bounce higher, and eventually leave the arena. Or liquid in the case of particles in a liquid. More heat and the balls bounce more and higher.