Question

question 2 of 10
how does one recognize a redox reaction?

a. by the presence of oxygen atoms
b. by changes in the oxidation states
c. by atoms rearranging in compounds
d. by the presence of ions in solution

Explanation:

A redox reaction involves oxidation (loss of electrons) and reduction (gain of electrons). The key indicator is changes in oxidation states of elements—some increase (oxidation) while others decrease (reduction). Oxygen presence (A) is not required (e.g., metal-displacement reactions). Atom rearrangement (C) describes all chemical reactions, not just redox. Ions in solution (D) relate to ionic reactions, not redox specifically.

Answer:

B. By changes in the oxidation states