Which of the following occurs as a result of an oxidation-reduction (redox) reaction?

• A. Only covalent bonds are broken and formed.
• B. Energy is always absorbed in the form of heat.
• C. Electrons are transferred from one species to another.
• D. Atoms are rearranged without any change in oxidation states.

Answer: (C)

Verified step by step guidance

1. Understand that an oxidation-reduction (redox) reaction involves changes in the oxidation states of atoms, which means electrons are transferred between species.
2. Recall that in redox reactions, one species loses electrons (oxidation) and another gains electrons (reduction). This electron transfer is the defining characteristic of redox processes.
3. Recognize that breaking and forming covalent bonds can occur in many types of reactions, not exclusively in redox reactions, so this is not a unique feature of redox.
4. Note that energy changes (heat absorption or release) can vary depending on the reaction and are not a guaranteed outcome of all redox reactions.
5. Understand that atoms being rearranged without changes in oxidation states describes a different type of reaction, such as a simple rearrangement or substitution, not a redox reaction.