Astudent wants to determine whether or not an unknown substance is a metal by testing its physical properties. which of the following properties would suggest that the substance is probably a metal?

oxidation reduction reaction or redox reactions are those in which there is change in oxidation number of any element

in general oxidation is defined as gain of oxygen or loss of electron or hydrogen by an atom. reduction is defined as gain of electron or hydrogen or loss of oxygen by an atom.

let us consider each reaction one by one

1)

here the oxidation number of w changes from +6 to 0 [reduction]

the oxidation number of h changes from 0 to +1 [oxidation]

hence it is an oxidation reduction reaction

2)

here there is no change in oxidation number of either element hence it is not oxidation reduction reaction

3)

here there is no change in oxidation number of either element hence it is not oxidation reduction reaction

4)

here there is no change in oxidation number of either element hence it is not oxidation reduction reaction

groups ivb–viii, ib, and iib, or 4–12