dikettahui massa atom relatif (Ar) Ca=40,C 12, O=16 maka massa molekul relatif CaCO3

Mr = Ar Ca + Ar C + Ar O
= 40 + 12 + (16×3)
= 52 + 48
= 100

Semoga membantu :}

Mr CaCO3 = (Ar Ca) + (Ar C) + (Ar O x 3)
= 40 + 12 + (16 x 3)
= 100