In a redox reaction, which of the following statements is correct?

• A. All reactants lose electrons.
• B. Both species gain electrons.
• C. No electrons are transferred between species.
• D. One species is oxidized while another is reduced.

Answer: (D)

Verified step by step guidance

1. Understand the definition of a redox reaction: it involves the transfer of electrons between two species.
2. Recall that oxidation is the loss of electrons, and reduction is the gain of electrons.
3. Recognize that in a redox reaction, one species must lose electrons (oxidized) and another species must gain electrons (reduced).
4. Evaluate the given statements: 'All reactants lose electrons' is incorrect because not all species lose electrons; some gain them.
5. 'Both species gain electrons' is incorrect because electrons cannot be gained by both; one must lose electrons.
6. 'No electrons are transferred between species' is incorrect because electron transfer is the defining feature of redox reactions.
7. Therefore, the correct statement is: 'One species is oxidized while another is reduced.'