Theo thuyết liên kết hóa trị VB (Valence Bond), liên kết N−H trong phân tử NH3 đượchình thành do sự xen phủ giữa các orbital: *

The answer is bhope this

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).