Final answer:
The statement is true; in redox reactions, for every molecule reduced another is oxidized, with electrons lost equal to electrons gained.
Step-by-step explanation:
The statement is true: Redox reactions occur simultaneously, and for every molecule that is reduced (gains electrons), another molecule is oxidized (loses electrons). In each redox reaction, the electrons that are lost by the oxidizing agent are the same in number as those gained by the reducing agent. This is because oxidation, defined as the loss of electrons, and reduction, defined as the gain of electrons, are complementary processes that always occur together. A balanced redox reaction ensures that the number of electrons lost by the reductant equals the number of electrons gained by the oxidant.
The change in oxidation numbers during a redox reaction reflects the transfer of electrons. An increase in the oxidation number indicates oxidation, while a decrease indicates reduction. At least two elements change their oxidation numbers during this process, reflecting that redox reactions involve a simultaneous change in the oxidation states of the atoms involved.