1)CaO =  40+16= 56

2)Ca3P2 = 40x3+31x2=182

3)CaSO3 = 40+32+16x3=

4)Ca(OH)2 = 40+(16+1)x2

5)Ca3(PO4)2 = 40x3+(31+16x4)x2

Сам порахуй скільки буде!

1)Mr(CaO)=56, W(Ca)=75%, W(0)=25%
2)Mr(Ca5P2)=262, W(Ca)=75%, W(P)=25%
3)Mr(CaSO5)=152, W(Ca)=26%, W(S)=21%, W(O)=53%
4)Mr(Ca(OH)2)=74, W(Ca)=54%, W(O)=43%, W(H)=3%
5)Mr(Ca5(PO4)2)=388, W(Ca)=52%, W(P)=16%, W(O)=32%

 W - массовую долю элемента

 це точно правельно