What is the color of chlorine?

Which of the following noble gases can diffuse through rubber?

Which of the following oxides of nitrogen is a neurotransmitter?

What happens when an atom of oxygen is subjected to external magnetic field?

Which of the following is most stable?

Which group 16 element is the most electronegative?

All halogens form only one oxoacid due to their high electronegativity and small size.

What is the temperature at which orthophosphoric acid forms pyrophosphoric acid?