Writing and Naming Compounds

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Valence Electron Noun

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[vay-lence i-lek-tron]

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Valence Electron

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An electron in the outermost energy level of an atom that participates in the formation of chemical bonds.

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Example: This diagram of an oxygen atom shows six electrons in its outermost shell; these are the valence electrons that determine how it bonds with other atoms.

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Ionization Energy Noun

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[ahy-uh-ni-zey-shuhn en-er-jee]

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Ionization Energy

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The amount of energy required to remove an electron from an isolated atom or molecule in its gaseous state.

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Example: This image shows energy being used to remove an electron from its outer shell in an atom, which is the definition of ionization energy.

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Electronegativity Noun

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[i-lek-troh-neg-uh-tiv-i-tee]

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Electronegativity

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A measure of the tendency of an atom to attract a bonding pair of electrons in a chemical bond.

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Example: This diagram shows that the greater the difference in electronegativity between two atoms, the more ionic the bond between them becomes.

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Ionic Bond Noun

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[ahy-on-ik bond]

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Ionic Bond

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A chemical bond formed by the electrostatic attraction between oppositely charged ions after an electron transfer between atoms.

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Example: A sodium (Na) atom loses an electron to a chlorine (Cl) atom, creating a positive ion (Na+) and a negative ion (Cl-) that attract to form an ionic bond.

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Covalent Bond Noun

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[koh-vey-luhnt bond]

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Covalent Bond

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A chemical bond that involves the sharing of electron pairs between atoms, typically occurring between non-metal elements.

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Example: Two hydrogen atoms and one oxygen atom share their outer electrons to form stable covalent bonds, creating a water molecule (H₂O).

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Metallic Bond Noun

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[muh-tal-ik bond]

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Metallic Bond

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A bond formed between positively charged metal ions and a surrounding 'sea' of delocalized, shared valence electrons.

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Example: This diagram shows a metallic bond, where positive metal ions are in a fixed pattern while their outer electrons are free to move throughout the metal.

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Anion Noun

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[an-ahy-on]

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Anion

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An ion that possesses a net negative charge, which is formed when a neutral atom gains one or more electrons.

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

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Cation Noun

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[kat-ahy-on]

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Cation

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An ion that possesses a net positive charge, which is formed when a neutral atom loses one or more electrons.

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Example: A neutral sodium atom (Na) loses its single valence electron, resulting in more protons than electrons and forming a positively charged ion, a cation (Na+).

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Polyatomic Ion Noun

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[pol-ee-uh-tom-ik ahy-on]

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Polyatomic Ion

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A charged chemical species composed of two or more atoms covalently bonded together that functions as a single unit.

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Example: This diagram shows a group of atoms (two phosphorus and seven oxygen) chemically bonded together, which acts as a single unit with a negative charge.

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Hydrate Noun

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[hahy-dreyt]

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Hydrate

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An ionic compound that has a specific number of water molecules chemically incorporated into its crystal lattice structure.

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Example: This diagram shows the lab setup for heating a hydrate, like copper(II) sulfate, to remove its water molecules, a key process in understanding these compounds.