Ответ:

Объяснение:

Mr(BaSO4) = 137 + 32 + 16*4 =233

W(Ba) = Ar(Ba) *n / Mr(BaSO4)  *100% = 137 *1 / 233  *100% =59%

W(S) = Ar(S) *n / Mr(BaSO4)  *100% = 32*1 / 233  *100% =14%

W(O) = Ar(O) *n / Mr(BaSO4)  *100% = 16*4 / 233  *100% = 27%