How many grams of sodium wil have the same number of atoms as 6 grams of magnesium
`("Given Na"=23u, Mg=24u)?`

Explanation

Number of grams- atoms of Mg = `("mass of Mg in atoms")/("gram-atomic mass") = (6g)/(24 g) = (1)/(4)`
`therefore` gram - atoms of sodium should be `(1)/(4)`
`because` 1 gram - atom of sodium = 23 g
`therefore (1)/(4)` gram-atom of sodium = `23 xx 1/4 g = 5.75 g` .