The characteristic way in which atoms of an element react is most related to the

A. number of electrons in the outermost shell.

B. number of electrons in the innermost shell.

C. number of neutrons in the nucleus.

D. size of the nucleus.

A. Number of electrons in the outermost shell

Explanation:

The outermost electrons are the farthest from the nucleus.

They are the least tightly held, so they are most likely to be involved in chemical reactions.

B. is wrong. The innermost electrons are too tightly held to react.

C. and D. are wrong. The particles in the nucleus do not take part in chemical reactions.