Redox reactions involve electron transfer or, more generally, changes in oxidation state. Oxidation and reduction always occur together.
Tracking oxidation numbers is a practical way to see which species loses electron density and which gains it.
Start with the central idea, then test it against a concrete element or example. A scientific model is useful when we know what it explains — and where its limits are.
Start with the central idea, then test it against a concrete element or example. A scientific model is useful when we know what it explains — and where its limits are.
Choose a concrete case linked to Oxidation and reduction. Write down the known information, what you are trying to find, and the units. Then state the rule, model or trend you will use. If a calculation is involved, keep the units visible at every line; if it is conceptual, state what changes and what remains fixed.
A strong answer contains four things: the starting situation, the variable that changes, the direction or numerical result, and one check. The check can be a unit, an order of magnitude, a limiting case or a comparison with a familiar example.