(NH₄)₂SO₄
M ((NH₄)₂SO₄) = 14*2 + 1*4*2+32+16*4 = 132
M ((NH₄)₂SO₄) = 28+8+32+64=132
W (N) = 28/ 132 *100 % = 21.21
W (H) = 8 / 132 * 100% = 6,06
W (S) = 32 / 132 * 100% = 24,24
W (O) = 64 / 132 * 100% = 48.48
ответ: 1 (N) - A
2 (H) - Д
3 (S)- В
4 (О) - Г