Hi:) for questions 8 & 9 , anyone able to explain why nitrogen is N2 instead of N. also why is chlorine cl2 instead of c1? Thank you!

What is a main difference between a mixture and a pure substance? a mixture is only a liquid, but a pure substance can be in any state.a mixture looks the same throughout, but a pure substance does not.1 a mixture can vary in composition, but a pure substance has a set composlo a mixture can be made up of a single compound, but a pure substance car