How many grams of magnesium will have the same number of atoms as 6 grams of carbon? (Mg = 24 u ; C = 12 u)

Mass of carbon = 6g

Equal moles of all substances contain an equal number of atoms

(1 mole of all substances contains 6.022 × 10²³ atoms).

To convert 6g  carbon into moles,

1 mole of carbon = 12g

12g  carbon = 1 mole

Therefore, 6g carbon = 0.5 moles

Since, equal moles of all substances contain an equal number of atoms, 0.5 moles of carbon will have the same number of atoms as present in 0.5 moles of magnesium.

To find out the mass of 0.5 moles of magnesium in grams.

1 mole of magnesium = 24g

0.5 moles of magnesium = 24 × 0.5 = 12g