Which statement concerning the mole is not correct?
| A mole of a diatomic element contains 2 × NA atoms of the element. |
| The molar mass of any compound is equal to its molecular weight in grams. |
| A mole of any compound contains one mole of each kind of atom found in that compound. |
| A mole of metal contains NA atoms of that metal. |
| All of these statements are correct. |