Answer : The correct answer is, Sublimation and Melting process.
Explanation :
Solid state : In this state, the molecules are closely and tightly packed. There is no vacant space present in it and there is strong inter-molecular force of attraction. The atoms are not free to move in this state.
Liquid state : In this state, the molecules are loosely packed and there is an intermediate vacant space present in it and there is less inter-molecular force of attraction. The atoms are free to move in this state.
Gas state : In this state, the molecules are very loosely packed and there is a lot of vacant space present in it and there is very less inter-molecular force of attraction. The atoms are easily free to move in this state.
So, there are two processes in which changes of state of atoms that cannot move past one another become free to move which are sublimation and melting process.
Sublimation : It is a process in which a solid directly changes to gaseous phase.
Melting : It is process in which a solid changes into liquid phase by providing heat.
<span>There are three states of matter: solid, liquid and gas. In solid state, atoms that make up the data are compact and do not move about. In liquid state, particle ha little force of attraction and are free to move about within the container containing the liquid. I gaseous state, atoms move about freely and there is no force of attraction between the atoms. The change of state from solid tog liquid is called melting while the change of state from solid to gas is called sublimation.</span>
