Answer:
27.74%
Step-by-step explanation:
The molar mass of Mg can be found on the periodic table: 24.31 g/mol.
To calculate the molar mass of Mg₃(PO₄)₂, we need to consider the individual elements' molar masses:
The molar mass of P is 30.97 g/mol.
The molar mass of O is 16.00 g/mol.
Molar mass of Mg₃(PO₄)₂ = 262 g/mol
Mass of Mg in Mg₃(PO₄)₂ = 24×3 = 72 g
percentage composition of Mg in Mg₃(PO₄)₂
(72*100) / 262 = 27.74%