[0307su]

I'm trying to figure out this one question that I can't answer.... It says...
Which statements are correct about Avogadro's constant, 6.02*10^23?
i) It is the number of atoms in 28g of CO
ii) It is the number of molecules in 2 grams of Helium, He
iii) it is the number of atoms in 1 gram of Hydrogen, H.

For what I think, I think the answer should be ii and iii but I wasn't sure if I was right or wrong... Can someone give me the correct answer and explain why??? Thank you.

[Borek]

What is molar mass of He? Do the He₂ exist?

[jeffmoonchop]

google the definition of avos constant, then you can calculate whether the mass of each material listed corresponds to its definition.