Which gas used for purifying, air in underground enterprises ?
What is chemical oxygen demand?
what is the relation between Total organic carbon and Chemical Oxygen demand?
Why does the water in tanks and ponds not freeze in winter ?
Why is clinical thermometer used in preference to and ordinary Fahrenheit thermometer ?
Why ate shadows longer at the end of the day ?
Why and how is short-circuit caused ?
Why are leaves of trees green ?
which gas is used in preaparation of bit salt
which acid present in soda water?
when we covert any substance into vapour state from solid state, is it ionized or not?
What can you contribute to the company?
how to do heavy metal test for colour sample?