Answer: Option A. ->
:

Filtration is commonly defined as the mechanical or physical operation used to separate insoluble solid particles from solid-liquid mixture due to the difference in the size of solid-liquid particles.
So, the most appropriate method of removing tea leaves after preparing tea is by filtration.
A tea strainer can be used to fulfill the above separation process. The smaller size of holes of the tea strainer does not allow solid particles to pass through them, but the liquid passes through it.

 

Answer: Option A. ->
:

Process name: 1 Mark
Explanation: 1 Mark
Evaporation takes place in this case.
Evaporation is a type of vaporization of the liquid that takes place from the surface of a liquid into the gaseous phase.
When the collected water is kept undisturbed in the pot, water is heated by sunlight and slowly turns into water vapour, through evaporation. In few days, the water evaporates completely.
$\therefore$ We do not see any water there after some days.

Answer: Option A. ->
:
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 the mixture can pass through the pores of the sieve whereas bigger components of the mixture are retained by the sieve.

Answer: Option A. ->
:

Definition: 1 Mark
Uses: 1 Mark
Churning is the process of shaking milk in order to convert it to butter.
It is used to extract butter from milk or curd. It is also used to churn butter from cream.

Answer: Option A. ->
:

Explanation: 1 Mark each
1. A mixture of sand and salt is taken in a beaker and water is added to it.
2. After a few seconds of stirring, since salt is soluble in water, the salt will dissolve into the water. 
3. The sand being heavier settles at the bottom of the beaker by a process which is known as sedimentation.
4. The sand can be separated from the salt solution by decantation or filtration.
5. The remaining mixture of salt and water is heated and the water evaporates to form water vapour.
6. Now, only salt is left into the beaker and the water vapour can be converted back into water through condensation.

Answer: Option A. ->
:

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 glass and 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.

Answer: Option A. ->
:

Explanation: 1 Mark each
There are various methods used for separating solid particles from substances. Some of them are:

1.Sedimentation

2.Decantation

3.Filtration

Sedimentation: The process of separating insoluble substances which are heavier than liquid by allowing them to settle down on their own due to gravity is called sedimentation. The particles which settle down during sedimentation are called sediments.
Decantation follows sedimentation. In this process, the clear upper liquid is poured out from the container without disturbing the sediment. The upper clear liquid is called supernatant.
Filtration is a process by which insoluble solids can be removed from a liquid by using a filter paper. 

Answer: Option A. ->
:

Steps: 1 Mark each. 
1. Iron nails can be separated from the mixture by handpicking (if the number of iron nails is low) or by magnetic separation.
2. Tea leaves can be separated from the mixture by filtration.
3. Oil can be separated from the mixture by sedimentation followed by decantation.
4. Salt can be obtained by evaporation of the water.
5. The evaporated water can be condensed and then retrieved.

Answer: Option C. -> separation
:
C

Handpicking stones from rice separates these two components. Thus, it is 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 separated from food items such as rice and lentils.

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.