Radioactivity and Half-Life

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Radioactivity Noun

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[ray-dee-oh-ak-tiv-i-tee]

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Radioactivity

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The spontaneous emission of radiation from an unstable atomic nucleus as it transforms to a more stable state.

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Example: This graph shows that after each 'half-life,' the amount of a radioactive substance decreases by half, demonstrating the predictable rate of radioactive decay.

Front

Isotope Noun

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[ahy-suh-tohp]

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Isotope

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Atoms of the same element with identical proton numbers but varying numbers of neutrons in their nuclei.

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Example: This image shows three forms of hydrogen: all have one proton, but they have different numbers of neutrons (0, 1, or 2).

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Nuclear Decay Noun

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[noo-klee-er dih-kay]

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Nuclear Decay

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The natural process where an unstable atomic nucleus transforms into another isotope by emitting radiation and releasing energy.

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Example: An unstable atomic nucleus (Uranium-235) spontaneously breaks apart, releasing a particle (alpha particle) and changing into a new, more stable nucleus (Thorium-231).

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Transmutation Noun

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[trans-myoo-tey-shuhn]

Back

Transmutation

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The conversion of an atom of one element into an atom of a different element through nuclear reactions.

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Example: A fast-moving alpha particle overcomes the repulsion of an atomic nucleus and merges with it, transforming the original atom into a new, heavier element.

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Standard Model Noun

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[stan-derd mod-l]

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Standard Model

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The established physics theory describing the fundamental particles of matter and the forces governing their interactions.

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Example: The Standard Model organizes the universe's fundamental particles, like quarks and electrons, which are the building blocks of matter, including radioactive atoms.

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Fundamental Particle Noun

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[fuhn-duh-men-tl pahr-ti-kuhl]

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Fundamental Particle

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An elementary particle that is not composed of smaller particles and serves as a basic building block of matter.

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Example: This diagram shows the fundamental particles (protons, neutrons, and electrons) that make up an atom, which are the key components involved in radioactive processes.

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Quark Noun

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[kwawrk]

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Quark

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A type of elementary particle that combines to form composite particles called hadrons, such as protons and neutrons.

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Example: This diagram shows that quarks are fundamental particles that combine to form larger particles, like protons (two up quarks, one down) and neutrons (one up quark, two down).

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Lepton Noun

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[lep-ton]

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Lepton

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A class of fundamental particles, including electrons and neutrinos, that do not experience the strong nuclear force.

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Example: This chart shows that leptons, like the electron, are a family of fundamental particles, distinct from other particles like quarks.

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Boson Noun

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[boh-son]

Back

Boson

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A type of subatomic particle that mediates the fundamental forces of nature, such as photons for electromagnetism.

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Example: This diagram shows that multiple bosons can be in the same place at the same time, like a pile of balls, unlike other particles (fermions).

Front

Proton Noun

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[proh-ton]

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Proton

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A stable, positively charged subatomic particle found in atomic nuclei, composed of two up quarks and one down quark.

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Example: This diagram shows a proton as a positively charged particle located inside the atom's central nucleus, along with uncharged neutrons.