Solutions, Acids, and Bases

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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 process in which an unstable atomic nucleus spontaneously emits charged particles and energy to become more stable.

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Example: An unstable parent nucleus (uranium-238) releases an alpha particle, transforming into a new, more stable daughter nucleus (thorium-234).

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Radioisotope Noun

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

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Radioisotope

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Any atom containing an unstable nucleus that undergoes radioactive decay, transforming into another isotope over time.

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Example: This diagram shows a radioactive atom (a radioisotope) is unstable, releasing energy, radiation, and particles as it breaks down, a process called radioactive decay.

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Nuclear Decay Noun

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[noo-klee-er di-kay]

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Nuclear Decay

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The spontaneous change of one isotope into another that occurs when the composition of a radioisotope's nucleus changes.

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Example: An unstable parent nucleus (uranium-238) releases an alpha particle, transforming into a new, more stable daughter nucleus (thorium-234).

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Nuclear Radiation Noun

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[noo-klee-er ray-dee-ey-shuhn]

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Nuclear Radiation

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Charged particles and high-energy rays that are emitted from the nuclei of radioisotopes during the process of nuclear decay.

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Example: A radioactive atom's unstable nucleus releases energy and particles, a process known as nuclear radiation.

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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, that is made up of two protons and two neutrons.

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Example: This diagram shows a large atomic nucleus releasing an alpha particle, which is made of two protons and two neutrons, during a process called alpha decay.

Front

Beta Particle Noun

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[bey-tuh pahr-ti-kuhl]

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Beta Particle

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A high-speed electron with a negative charge that is emitted by an unstable nucleus during the process of beta decay.

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Example: This diagram shows a nucleus undergoing beta decay, a process where it emits a high-energy electron known as a beta particle.

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Gamma Ray Noun

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[gam-uh rey]

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Gamma Ray

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A penetrating ray of high-frequency electromagnetic energy emitted by an unstable nucleus, which has no mass and no charge.

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Example: An excited atomic nucleus releases energy by emitting a high-energy light particle, called a gamma photon, to become a stable, relaxed nucleus.

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Neutrino Noun

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[noo-tree-noh]

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Neutrino

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A subatomic particle with very little mass that is emitted along with a beta particle during beta decay.

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Example: This diagram shows that during beta-plus decay, a proton in an atom's nucleus changes into a neutron, releasing a positron and a neutrino.

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Ionizing Radiation Noun

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[ahy-uh-nahy-zing ray-dee-ey-shuhn]

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Ionizing Radiation

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Forms of radiation, such as alpha and beta particles, that possess enough energy to remove electrons from atoms.

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Example: This image shows the basic structure of a neutral atom, with a nucleus containing protons and neutrons, and electrons orbiting the nucleus.

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Background Radiation Noun

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[bak-ground ray-dee-ey-shuhn]

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Background Radiation

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Nuclear radiation that occurs naturally in the environment from sources like rocks, air, water, and cosmic rays.

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Example: This donut chart shows the different sources of background radiation we are exposed to, with radon gas from the ground being the largest source.