Questions

Light year is the unit of to express astronomical distances, that light can travel in one year. Light moves at a velocity of about 300,000 kilometers (km) each second. So in one year, it can travel about 10 trillion km. More precisely, one light-year is equal to 9,500,000,000,000 kilometers.

Approximately, 1 light year = 10^16 mts.

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.

The main use of salt in the diet is to produce in small amounts the hydrochloric acid required for the digestion of food.

Sum of all numbers in each row and columns must be 15.

In last row to gt sum as 15 missing number must replaced by 1.