Final answer:
Oxidation is the loss of electrons, gain of oxygen, or loss of hydrogen, while reduction is the gain of electrons, loss of oxygen, or gain of hydrogen. These processes are coupled in redox reactions, with oxidation also corresponding to an increase in oxidation state and reduction to a decrease. The correct statement in the context of the question is that oxidation is the loss of electrons and reduction is the gain of electrons.
Step-by-step explanation:
Oxidation and reduction are two halves of a type of chemical reaction called an oxidation-reduction or redox reaction. These reactions involve the transfer of electrons between reactants, leading to changes in their oxidation states.
Oxidation is defined as the loss of electrons. It can also be conceptualized as the gain of oxygen or the loss of hydrogen by a molecule, atom, or ion. On the other hand, reduction is the gain of electrons, which inversely can be seen as the loss of oxygen or the gain of hydrogen. These definitions are summarized by the mnemonic 'OIL RIG,' which stands for 'Oxidation Is Loss, Reduction Is Gain' of electrons. Additionally, oxidation can be associated with an increase in oxidation state, while reduction corresponds to a decrease in oxidation state.
To address the specific options provided in your question: B) Oxidation is the loss of electrons, and reduction is the gain of electrons is a correct statement. D) Oxidation involves an increase in oxidation state, and reduction involves a decrease in oxidation state is also a valid way to understand these processes.
It's essential to note that these processes occur simultaneously; when one substance is oxidized, another is reduced in a complementary manner. Therefore, redox reactions are always coupled, with the electron donor being oxidized and the electron acceptor being reduced.