Radioactive Decay

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Nucleons Noun

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[noo-klee-ons]

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Nucleons

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The protons and neutrons that are collectively found within the dense nucleus of an atom.

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Example: This diagram shows that the nucleus of an atom is made of protons and neutrons, which are collectively called nucleons.

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Unstable Adjective

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[un-stey-buhl]

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Unstable

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A state describing an atom that is spontaneously radioactive and will undergo decay to achieve a more stable configuration.

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Example: This graph shows that an unstable substance decays over time, with half of it remaining after each 'half-life,' illustrating the process of radioactive decay.

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Strong Nuclear Force Noun

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[strong noo-klee-er fors]

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Strong Nuclear Force

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A fundamental attractive force that binds nucleons together in the nucleus, overcoming the electrostatic repulsion between protons at close range.

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Example: The strong nuclear force is an attraction that holds protons and neutrons together in an atom's nucleus, overcoming the electrostatic repulsion between positively charged protons.

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Neutron-to-Proton Ratio Noun

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[noo-tron-too-proh-ton rey-shee-oh]

Back

Neutron-to-Proton Ratio

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The ratio of the number of neutrons to the number of protons within an atom's nucleus, a key factor in nuclear stability.

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Example: This image shows three carbon atoms. As neutrons are added while protons stay the same, the neutron-to-proton ratio increases, which can make the atom unstable.

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Band of Stability Noun

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[band uv stuh-bil-i-tee]

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Band of Stability

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A region on a plot of neutrons versus protons that contains all known stable atomic nuclei.

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Example: This graph plots neutrons versus protons, showing that stable atoms exist only in a narrow 'band of stability' and not in any random combination.

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Radioactive Decay Noun

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[rey-dee-oh-ak-tiv di-key]

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Radioactive Decay

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The spontaneous process through which an unstable atomic nucleus loses energy by emitting radiation to become more stable.

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Example: An unstable parent nucleus releases an alpha particle (two protons and two neutrons), transforming into a more stable daughter nucleus.

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Transmutation Noun

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[trans-myoo-tey-shuhn]

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Transmutation

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The conversion of an atom of one element into an atom of another element through a nuclear reaction.

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Example: This diagram shows a Uranium atom changing into a Neptunium atom, and then into a Plutonium atom, demonstrating how one element can transmute into another.

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Radioisotope Noun

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[rey-dee-oh-ahy-suh-tohp]

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Radioisotope

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An isotope of an element that is unstable and spontaneously emits radiation as it undergoes radioactive decay.

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Example: An unstable radioisotope, like uranium-238, decays by releasing a particle (alpha particle) and changes into a different, more stable element (thorium-234).

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Alpha Decay Noun

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[al-fuh di-key]

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Alpha Decay

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A type of radioactive decay where an atomic nucleus emits an alpha particle, transforming into a different atomic nucleus.

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Example: An unstable parent atom's nucleus releases an alpha particle (2 protons, 2 neutrons), changing into a new, smaller daughter nucleus.

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Alpha Particle Noun

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[al-fuh pahr-ti-kuhl]

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Alpha Particle

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A positively charged particle, identical to a helium nucleus, consisting of two protons and two neutrons emitted during alpha decay.

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Example: A large, unstable radioactive nucleus (Uranium-238) emits an alpha particle (two protons and two neutrons) to become a new, smaller nucleus (Thorium-234).