An atom is considered electrically reactive when it has a strong tendency to gain, lose, or share electrons to achieve a stable electron configuration. This is because the atom is trying to achieve a full outer shell of electrons, which makes it more stable and less likely to react with other atoms.

Here's a breakdown of what makes an atom electrically reactive:

* Unfilled outer shell: Atoms with incomplete outer shells of electrons have a high tendency to react. They want to gain or lose electrons to fill their outer shell and reach a stable configuration like the nearest noble gas.

* Electronegativity: This is a measure of an atom's ability to attract electrons in a chemical bond. Atoms with high electronegativity tend to gain electrons, while atoms with low electronegativity tend to lose electrons.

* Ionization energy: This is the energy required to remove an electron from an atom. Atoms with low ionization energy easily lose electrons and become positively charged ions.

* Electron affinity: This is the change in energy when an electron is added to a neutral atom. Atoms with high electron affinity readily gain electrons and become negatively charged ions.

Examples:

* Sodium (Na): Has only one electron in its outer shell. It readily loses this electron to become a positively charged Na+ ion, which has a stable electron configuration like neon (Ne).

* Chlorine (Cl): Has seven electrons in its outer shell. It readily gains one electron to become a negatively charged Cl- ion, which has a stable electron configuration like argon (Ar).

Therefore, an atom's electrical reactivity is directly related to its ability to participate in chemical reactions by gaining, losing, or sharing electrons to achieve a stable electron configuration.