Question

The reactivity of an atom arises from __________.

A) the average distance of the outermost electron shell from the nucleus

B) the existence of unpaired electrons in the valence shell

C) the sum of the potential energies of all the electron shells

D) the potential energy of the valence shell

E) the energy difference between the s and p orbitals

Answer 1

The reactivity of an atom mostly comes from having unpaired electrons in its valence shell, as it makes the atom inclined to interact with other atoms to fill or empty its outer shell.

Step-by-step explanation:

The reactivity of an atom arises from the existence of unpaired electrons in the valence shell. The valence shell is the outermost shell of an atom that contains the electrons most likely to be involved in chemical reactions. If the valence shell is not full, meaning it has unpaired electrons, the atom is more reactive because it will tend to react with other atoms in ways that complete its valence shell.

Atoms with a full valence shell are stable and chemically inert, while atoms with one or two electrons more or less than a full shell are highly reactive. This reactivity is due to the atom's tendency to lose or gain electrons to form ions, or to share electrons to form covalent bonds.