\(aPTK_{hc}=PTK_{O_2}.2=2.2.NTK_O=2.2.16=64\left(đ.v.C\right)\\ b.PTK_{hc}=NTK_X+2.NTK_O=NTK_X+2.16=NTK_X+32\left(đ.v.C\right)\\ \Rightarrow NTK_X+32=64\\ \Leftrightarrow NTK_X=64-32=32\left(đ.v.C\right)\\ \Rightarrow X:Lưu.huỳnh\left(KHHH:S\right)\)