In an oxidation-reduction reaction, the substance reduced always \[ \begin{array}{l}\text { shows a gain of electrons. } \\ \text { becomes a charged species. } \\ \text { gives up hydrogen atoms. } \\ \text { Submit takes on oxygen atoms. } \\ \text { Request Answer }\end{array} \]

The substance that is reduced in an oxidation-reduction reaction indeed shows a gain of electrons. This process effectively reduces the overall positive charge of the species, often leading to a more stable state. In many cases, this can involve a gain of hydrogen atoms, which can further contribute to the reduction of a substance. Moreover, oxidation-reduction reactions are not just a lab phenomenon; they are behind some of the biggest processes in our world. For instance, photosynthesis in plants relies on redox reactions, where carbon dioxide is reduced to glucose while water is oxidized to oxygen. This foundational process supports life on Earth, demonstrating the importance of understanding these reactions.