Which of an atom's electrons are involved in chemical reactions?

O

A. The electrons farthest from the nucleus of the atom

O

B. The electrons that make one isotope different from another

O

C. The electrons closest to the nucleus of the atom

O

D. The electrons that determine the atomic number of the atom

The answer is A. The electrons farthest from the nucleus of the atom.

Explanation: If the outer most layer is full of electrons then it is less reactive. If the layer has few electrons, it has more room to bond with other elements and react.

In all ...

More on the outside the less reactive it is.

Less on the out side the more reactive it is.