One reactant gets oxidised while the other gets reduced during a reaction. Such reactions are called:

Both Option 1 and Option 2 are correct

The correct answer is option 3. Both Option 1 and Option 2 are correct.

In chemistry, we encounter reactions where electrons are transferred between reactants. These reactions are fundamental and have a special name: Oxidation-Reduction (Redox) reactions. Let's break down what this means:

Oxidation: Imagine a scenario where an atom or ion loses one or more electrons during a reaction. We say this atom or ion has been oxidized. It's like it's given away some of its negative charge, making it become more positive (higher oxidation state).

Reduction: On the other hand, if an atom or ion gains one or more electrons during the reaction, we say it's been reduced. In this case, it's like it's acquired a negative charge, making it become more negative (lower oxidation state).

Here's the key point: Oxidation and reduction always happen together. You can't have one without the other. The electrons lost by something (oxidation) must be gained by something else (reduction) to maintain overall electrical balance in the reaction.

Option 1: Oxidation-Reduction Reactions

This term explicitly mentions both oxidation and reduction, accurately describing the two processes happening simultaneously within the reaction.

Option 2: Redox Reactions

"Redox" is a shorthand term combining "reduction" and "oxidation." While shorter, it still implies both processes are occurring.

Therefore, both Option 1 and Option 2 are correct.  

They represent the same concept from different perspectives. Oxidation-reduction is more descriptive, while Redox is a concise term for the same phenomenon.