Ions

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Neutral Atom Noun

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[noo-truhl at-uhm]

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Neutral Atom

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An atom that has an equal number of protons and electrons, resulting in a net electrical charge of zero.

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Example: This diagram shows a neutral oxygen atom, which has an equal number of positively charged protons (8) and negatively charged electrons (8), resulting in no overall charge.

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Octet Rule Noun

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[ok-tet rool]

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Octet Rule

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The principle that atoms tend to gain, lose, or share electrons to achieve a full outer shell with eight electrons.

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Example: This diagram shows a sodium atom has one electron in its outer shell. To become stable (the octet rule), it will lose this electron.

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Valence Electrons Noun

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[vey-luhns ih-lek-trons]

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Valence Electrons

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The electrons located in the outermost energy level of an atom, which are involved in forming chemical bonds and ions.

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Example: This atomic model shows that valence electrons are the electrons located in the outermost shell of an atom, while core electrons are in the inner shells.

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Ion Noun

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[ahy-on]

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Ion

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An atom or group of atoms that has a net electrical charge due to the loss or gain of electrons.

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Example: A neutral sodium atom (Na) with equal protons and electrons becomes a positively charged sodium ion (Na+) when it loses one electron.

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Cation Noun

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[kat-ahy-on]

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Cation

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A positively charged ion that is formed when a neutral atom loses one or more of its valence electrons.

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Example: A neutral sodium (Na) atom loses its outer electron, becoming a positively charged sodium ion (Na+), which is a cation.

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Anion Noun

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[an-ahy-on]

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Anion

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A negatively charged ion that is formed when a neutral atom gains one or more electrons in its valence shell.

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Example: A neutral chlorine atom gains an electron to fill its outer shell, becoming a negatively charged chloride anion (Cl⁻).

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Valence Shell Noun

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[vey-luhns shel]

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Valence Shell

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The outermost electron-occupied shell of an atom, which holds the electrons that determine the atom's chemical properties and reactivity.

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Example: This atomic model shows the outermost electron shell, the valence shell, which contains valence electrons that can be lost or gained to form an ion.

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Fluoride Noun

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[floo-uh-rahyd]

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Fluoride

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The negatively charged anion of fluorine, with the symbol F⁻, formed when a fluorine atom gains one electron.

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Example: This image explains how fluoride protects teeth from acid caused by bacteria and sugar, but it does not illustrate the chemical properties of a fluoride ion.

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Oxide Noun

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[ok-sahyd]

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Oxide

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The negatively charged anion of oxygen, with the symbol O²⁻, formed when an oxygen atom gains two electrons.

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Example: This table lists seven different types of nitrogen oxides, showing their chemical formulas, molecular structures, and physical properties.

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Nitride Noun

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[nahy-trahyd]

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Nitride

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The negatively charged anion of nitrogen, with the symbol N³⁻, formed when a nitrogen atom gains three electrons.

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Example: The image shows a nitride ion (N³⁻) is a single nitrogen atom with a 3- charge, distinguishing it from related ions containing oxygen.