Which of the following has least mass: 2 g atom of nitrogen, 3*10^23 atoms of C, 1 mole of S, 7 g of Ag?

Q. Which has the highest mass ?
(a) 50 g iron (b) 5 moles of $N_2$
(c) 0.1 mol atom of Ag (d) ${10}^{23}$ atoms of carbon

Q. Which of the following has maximum number of atoms?
a)0.5 g atoms of Cu
b)0.635g of Cu
c)0.25 moles of Cu atoms
d)1g of Cu

Q. The number of atoms present in 0.5 mole of nitrogen is same as the atoms in:
(a)12 g of C (b) 64 g of S
(c) 8 g of O (d) 48 g of mg

Q. Fill in the following blanks :
(a) 1 mole contains ...................... atoms, molecules or ions of a substance.
(b) A mole represents an ..................... number of particles of a substance.
(c) 60 g of carbon element are ................... moles of carbon atoms.
(d) 0.5 mole of calcium element has a mass of ......................
(e) 64 g of oxygen gas contains ....................... moles of oxygen atoms.