Questions

True, Air is a Mixture.

Air is considered as mixture for the following reasons ;

1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air.

2. Air shows the properties of all the gases present in the atmosphere.
For example : Oxygen is good Supporter of combustion. Hence air also is good supporter of combustion.

3. Air does not have a fixed formula.

4. Air has a variable composition because air at different places contains different amount of gases.

5. Heat or Light energy is neither absorbed nor released when air is prepared physical by mixing required amount of gases .

6. Mixture does have fixed boiling Point. It holds good in case of liquid air.

There are 8 different types of Soils present in India. They are primarily differentiated on the basis of composition and structure. They are ::

1.  Alluvial soils, 

2.  Black soils,

3.  Red soils,

4.  Laterite and Lateritic soils,

5.  Forest and Mountain soils,

6.  Arid and Desert soils,

7.  Saline and Alkaline soils and

8.  Peaty and Marshy soils.

Stratification as actually the settling down of sediments with different properties to form layers/strata over years. Stratification especially occurs on the bed of water bodies such as oceans.

Stratified sedimentary rocks are used to study the ecological conditions over previous years/eras.  

The other choices like Windstorms, Glacial Ice and Stream water are mediums which sediments are transported.

Half the Product of Number in the upper & lower box gives the number in the middle box.

i.e. 18 x 4/2 = 36

15 x 6/2 = 45

In the same way 

8 x N/2 = 44 => N = 11.