Magnesium and iron are metallic elements. How does a mole of magnesium compare with a mole of iron?

A mole of any element contains the same number of atoms: about 6.02 × 10²³. So a mole of magnesium and a mole of iron have the same number of atoms, even though iron atoms are heavier and a mole of iron has more mass. The correct choice is “They both have the same number of atoms.”

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