Which of the following is a simple definition of oxidation? the loss of electrons the gain of electrons an agent that oxidizes something an agent that reduces something

The right answer is the loss of electrons.

In the oxidation reaction, the loss of electrons is in favor of another reagent called "oxidant".

Thus, rust (a mixture of oxides and hydroxides of iron) is the result of the oxidation of iron.

This can be, for example, the following reaction:

Fe → Fe2 + + 2e-

Fe2 + ion is the oxidized form of iron. The opposite reaction is then called a "reduction reaction".

your answer is "the 1950's"