Select the number that can replace the question mark (?)

For making of parachute, which polymeric substance used?

Who discovered the atomic nucleus?

Which vitamin exists  in the Cobalt   ?

Which statement about carbon credits is incorrect?

______ is defined as the number of moles of solute per litre of solution.

Pentane has _____ structural isomers.

Which alloy is formed by mixing iron with carbon, nickel, and zinc?

Which material is used as a moderator in a nuclear power plant that slows down the neutrons and makes them fit for causing fission?

What term is used for atoms that have the same number of protons but different numbers of neutrons?

Lexan is a man-made polymer used for making