Answer: Option C. -> filtration
:
C
Filtration helps to remove the suspended impurities.The mixture whichcontain insoluble solid particles suspended in a liquidare passed througha filter paper.The filter paper has minute pores that trap the solid particles.
In the given example, the size of tea leaves are large enough, so they can be easily separated from the prepared teaby filtration.

:
Reason: 1 Mark
Process name: 1 Mark
Mechanism: 1 Mark
By beating bundles of wheat, the farmer is trying to free the grain seeds from thestalks and this process is known as threshing.
Grains are attached at the weakest links of the stalk. As bundles of stalks are beaten, grains detach from the stalk and fall apart.
Threshingcan be performed manually or with the help ofmachines.

Answer: Option C. -> Sand
:
C
Salt, sugar and coffee powder can easily dissolve in water. They form homogeneous solution. Whereas sand particles settle down. Thus sand is insoluble in water.

Answer: Option B. -> False
:
B
Separation is done:
1.To remove unwanted substances
2.To get useful substances
3.To remove impurities
Hence, the given statement is false.

Answer: Option A. -> residue
:
A
The filter paper acts as a sieve allowing tiny liquid particles to pass through. Tiny pores in the filter paper restrict the flow of larger solid particles. These solid particles arecollectively known as residue.

Answer: Option B. -> Decantation
:
B
Sieving, threshing and winnowing are separation techniques utilised to separate solid-solid mixtures. A solid-liquid mixture and a mixture of immiscible liquids can be separated bydecantation.

:
Explanation: 1 Mark each.
1. This phenomenon of water droplets being formed on a cool water bottle is called condensation.
2. Condensation happens because of the temperature difference. The water vapour present in the air cools down due to the low temperature of water inside the glassand forms small droplets of water on the surface of the glass.
3. The reverse of this phenomenon is liquid being turned into gas, and this process can happen.
4. This process is called evaporation. Evaporation is the conversion of a liquid into a gas by application of heat.
5. Example: Heating water turns it into steam.

:
Definitions: 1 Mark each
Any three:
Handpicking
It involves simply picking out substances by hand and separating them from other substances.
Threshing
This is done after harvesting of crops. Once wheat is harvested, the stalks are dried. Then, the dry stalks are beaten so that the dried grains inside the stalks shake off and fall out.
Winnowing
It is the process of clearing the grains of the husk and chaff before grinding into flour. The farmer gently drops the mixture to the ground from a height. The heavier grains are collected at a place, while the lighter chaff blows away.
Sieving
Sieving is used to separate substances that are of different sizes. It is also called filtering. In this method, a sieve is used. The smaller components of themixturecan pass through the pores of the sieve whereas bigger components of themixtureare retained by the sieve.

Answer: Option A. -> True
:
A
Solubility increases on heating the solution. This means, more solute can be added to the solution on increasing the temperature.

Answer: Option C. -> separation
:
C
Handpicking stones from rice separates these two components. Thus, itis a process of separation. Handpicking is useful in separating the components which have difference in appearance in terms of shape, size, colour, etc. For example, at our homes, stones are separatedfrom food items such as rice and lentils.