Two substances A and B were made to react to form a third substance, ${\text{A}}_{\text{2}}\text{B}$ according to the following reaction. $2\text{A}+\text{B}\to {\text{A}}_{\text{2}}\text{B}$

Which of the following statements concerning this reaction are incorrect?

I) The product ${\text{A}}_{\text{2}}\text{B}$  shows the properties of substances A and B.

II) The product will always have a fixed composition.

III) The product formed cannot be classified as a compound.

IV) The product formed is an element.