Ionic and Covalent Bonding

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Chemical Bond Noun

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[kem-i-kuhl bond]

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Chemical Bond

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An attraction between atoms that allows the formation of chemical substances by sharing or transferring electrons to achieve stability.

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Example: This diagram shows two hydrogen atoms and one oxygen atom sharing their outer electrons to form strong connections, called covalent bonds, creating a water molecule.

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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 that are directly involved in forming chemical bonds.

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Example: This Bohr model of a Sodium atom shows its electrons in shells. The single electron in the outermost shell is its valence electron.

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Compound Noun

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[kom-pound]

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Compound

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A substance formed when two or more different chemical elements are chemically bonded together in a fixed ratio.

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Example: This diagram shows a carbon dioxide (CO₂) molecule, an example of a compound where one carbon atom is chemically bonded to two oxygen atoms.

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Chemical Formula Noun

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[kem-i-kuhl fawr-myoo-luh]

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Chemical Formula

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A representation of a substance using chemical symbols for its elements and subscripts for the number of atoms.

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Example: This image shows a glucose molecule and its chemical formula, C₆H₁₂O₆. The formula is a code telling you it has 6 carbon, 12 hydrogen, and 6 oxygen atoms.

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Electronegativity Noun

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[ih-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 scale shows how the difference in electronegativity between two atoms determines the type of bond they form, ranging from nonpolar covalent to ionic.

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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 through electrostatic attraction between two oppositely charged ions, typically a metal and a non-metal.

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Example: A sodium (Na) atom transfers an electron to a chlorine (Cl) atom, forming a positive sodium ion (Na+) and a negative chloride ion (Cl-).

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Ion Noun

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[ahy-on]

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Ion

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An atom or molecule that possesses a net electric charge due to the loss or gain of one or more electrons.

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Example: A neutral sodium atom (Na) with 11 protons and 11 electrons becomes a positive sodium ion (Na+) by losing one electron, resulting in a 1+ charge.

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Crystalline Lattice Noun

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[kris-tuh-lin lat-is]

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Crystalline Lattice

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The symmetrical three-dimensional arrangement of atoms, ions, or molecules in a crystalline solid, characteristic of ionic compounds.

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Example: The image shows a crystalline solid (left) where atoms are arranged in a highly ordered, repeating pattern, which defines a crystalline lattice.

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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 two non-metals.

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Example: Two non-metal atoms share their outer electrons (valence electrons) to form a stable bond, creating a covalent molecule.

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Molecule Noun

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[mol-i-kyool]

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Molecule

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An electrically neutral group of two or more atoms held together by strong covalent chemical bonds.

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Example: This diagram shows a single water molecule, where one oxygen atom is covalently bonded to two hydrogen atoms, forming a distinct unit.