An ion is defined as ...

An ion is defined as ...

• A. An electrically charged particle.
• B. A neutral atom.
• C. A photon.
• D. A molecule of gas.

Answer: (A)

An ion is defined by carrying a net electric charge because its number of electrons does not equal its number of protons. When electrons are lost, the particle becomes positively charged; when electrons are gained, it becomes negatively charged. This charged state is what distinguishes ions from neutral atoms or neutral molecules. Photons are particles of light and are not charged in the same way, and a molecule of gas is typically neutral unless it has gained or lost electrons to become an ion.

An ion is defined by carrying a net electric charge because its number of electrons does not equal its number of protons. When electrons are lost, the particle becomes positively charged; when electrons are gained, it becomes negatively charged. This charged state is what distinguishes ions from neutral atoms or neutral molecules. Photons are particles of light and are not charged in the same way, and a molecule of gas is typically neutral unless it has gained or lost electrons to become an ion.