Question

The process in which a solid changes directly into gas is called:
A.Decantation
B.Sublimation
C.Condensation
D.Sedimentation

Answer 1

Sublimation: The process of conversion of solid to gas without undergoing to liquid phase, is known as sublimation.
Condensation: The process of conversion of gas to liquid, is known as condensation.

Complete answer:
There are mainly three states of matter known as: solids, liquids and gases.
Solids: Solids are those states of matter which have definite shape and definite volume. Fixed shape means if we place them in any container then their shape will not change. It will be the same as before.
Liquids: Liquids are those states of matter whose atoms or particles are held together by intermolecular force which is less than that of forces in solids.
Gases: Gases are those states of matter whose atoms or particles are held together by a very weak force of attraction i.e. vanderwaal force of attraction which is less than that of forces in solids and in liquids. Gases do not have definite volume and do not have definite shape.
Sedimentation: It is defined as the process to remove suspended solid particles from using gravity, is known as sedimentation. For example: removal of sand or salt from water.
Decantation: It is defined as the process for the separation of mixtures of immiscible liquids (which are not miscible), known as decantation.
The conversion of solid to liquid is known as melting, conversion of solid to gas without going into liquid phase is known as sublimation, conversion of liquid to solid is known as freezing or solidification, conversion of liquid to gas is known as vapourization, conversion of gas to solid without going to liquid phase is desublimation and conversion of gas to liquid is known as condensation.
The process in which a solid changes directly into gas is called sublimation.

Hence option B is correct.

Note:
Miscible liquids: The liquids that combine in any ratio to form a homogenous solution. For example: ethanol and water are miscible liquids because we can add as much water we want to add.
Immiscible liquids: The liquids which do not mix to give a homogenous mixture, are known as immiscible liquids.