Ionic Reactions

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Chemical Change Noun

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[kem-i-kuhl cheynj]

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Chemical Change

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A process where substances transform into new substances with different compositions and properties, also known as a chemical reaction.

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Example: When hydrochloric acid is added to iron powder, a chemical change occurs, creating a new substance and releasing gas bubbles.

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Precipitate Noun

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[pri-sip-i-teyt]

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Precipitate

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An insoluble solid that emerges from a liquid solution during a chemical reaction when two solutions are mixed.

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Example: This diagram shows a process where a solid, the precipitate, forms and settles at the bottom of a liquid solution.

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Redox Reaction Noun

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[ree-doks ree-ak-shun]

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Redox Reaction

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A type of chemical reaction that involves the full or partial transfer of electrons from one reactant to another.

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Example: This diagram shows a redox reaction where substance A is oxidized by losing an electron, and substance B is reduced by gaining that same electron.

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Oxidation Noun

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[ok-si-dey-shun]

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Oxidation

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The process involving the full or partial loss of electrons or the gain of oxygen by a substance during a reaction.

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Example: This diagram shows an experiment to find what causes a nail to rust (oxidize), comparing conditions with and without water and air.

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Reduction Noun

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[ri-duhk-shun]

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Reduction

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The process involving the full or partial gain of electrons or the loss of oxygen by a substance during a reaction.

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Example: This diagram shows oxygen (O₂) turning into an oxide ion (O²⁻) by gaining electrons, which is the process of reduction.

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Half-reaction Noun

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[haf ree-ak-shun]

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Half-reaction

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An equation showing either the oxidation or the reduction part of a redox reaction, detailing the electron transfer process.

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Example: This diagram shows a full reaction split into two parts: a zinc atom losing electrons (oxidation half-reaction) and a copper ion gaining them (reduction half-reaction).

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Ion Noun

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[ahy-on]

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Ion

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An atom or a group of bonded atoms that has an overall electrical charge from losing or gaining electrons.

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Example: A neutral sodium atom (Na) with an equal number of 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 atom loses one electron from its outer shell, resulting in more protons than electrons and creating a positively charged ion called 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 into 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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Atomic Radii Noun

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[uh-tom-ik rey-dee-ahy]

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Atomic Radii

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A measure of the size of an atom, typically the mean distance from the nucleus to the outermost electron shell.

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Example: The atomic radius is half the measured distance between the nuclei of two identical, bonded atoms.