Explanation

Use a comma before while in the middle of a sentence when you mean “whereas” or “although.

Explanation

Hazrat Khadija's (رضہ) Father's name was Khuwaylid ibn Asad and their mother's name was Fatima bint zaidah

Khadijah's father was a merchant and leader.

"Hazrat Khadija's"  important Questions and information

Explanation

The device that is used to measure temperature is called Thermometer .

Temperature measurement (also known as thermometry) describes the process of measuring a current local temperature for immediate or later evaluation. 

Explanation

Groundwater is water that exists underground in saturated zones beneath the land surface.

Explanation

It is made of O3 

Oxygen layer in atmosphere

Ozone protects us from the harmful ultraviolent radiations of the sun.

Ozone formula : O3

Explanation

It is  Exclamatory Sentence due to sign / mark of Exclamation (!) 

Explanation

320/4=80

Explanation

She has not been working for two hours

وہ دو گھنٹے سے کام نہیں کر رہی۔

Explanation

Chemical reactions that take place inside living things are called biochemical reactions. 

An enzyme is a substance that acts as a catalyst in living organisms, regulating the rate at which chemical reactions proceed without itself being altered in the process.

Explanation

The symbol of mercury is Hg .

Freezing point of mercury is -38.83C.

Boiling point of Mercury is 356.7 C.