Which of the following is used as raw material for the manufacture of rayon?

What happens in most toothpastes to prevent tooth decay?

.______ is least reactive element belonging to group 17.

Which of the following are metals found in free state in the earth's crust?

The gas which is present in both the natural gas and the bio-gas is

Of the options listed below, the speed of sound is highest in _____ at 25°C. 

Read the following questions carefully and answer them. 

The gas used for artificial fruit ripening of green fruit is —

Fe has 26 protons in its nucleus. What are the number of electrons in Fe²⁺ (II) ion?