Which of the following contains the maximum number of molecules?

CHEMISTRY · Single correct · A Level · Chemistry · Amount of substance · Amount of substance

Problem

Which of the following contains the maximum number of molecules? (1)

4\,\text{g}

of hydrogen (2)

22.4\,\text{L}

of oxygen at STP (3) Carbon dioxide obtained by heating

1

mole of calcium carbonate (4)

4\,\text{g}

of helium