Ions and Isotopes

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Atom Noun

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[at-uhm]

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Atom

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The basic unit of a chemical element, consisting of a central nucleus surrounded by one or more negatively charged electrons.

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Example: This diagram shows an atom's structure, with a central nucleus containing protons and neutrons, and electrons orbiting in shells, establishing the baseline for understanding ions and isotopes.

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Nucleus Noun

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[noo-klee-uhs]

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Nucleus

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The dense, positively charged central region of an atom, which is composed of protons and neutrons and contains its mass.

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Example: The nucleus is the dense central core of an atom, containing positively charged protons and neutral neutrons, as shown in this diagram.

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Proton Noun

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[proh-ton]

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Proton

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A stable subatomic particle located in the nucleus of an atom, possessing a positive electric charge of one unit.

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Example: This diagram shows a proton as a positively charged (+) particle located in the central nucleus of an atom, along with neutrons and orbiting electrons.

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Neutron Noun

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[noo-tron]

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Neutron

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A subatomic particle found in the nucleus of an atom, having no electric charge and a mass similar to a proton.

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Example: This diagram shows a neutron as a neutral particle (no charge symbol) located inside the atom's central nucleus, alongside positively charged protons.

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Electron Noun

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[ih-lek-tron]

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Electron

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A stable subatomic particle with a negative electric charge, found in orbitals surrounding the nucleus of an atom.

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Example: This Bohr model shows electrons as blue dots orbiting the nucleus of a sodium atom in distinct energy shells, or levels.

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Subatomic Particle Noun

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[sub-uh-tom-ik par-ti-kuhl]

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Subatomic Particle

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A particle of matter that is smaller than an atom, including constituents like protons, neutrons, and electrons.

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Example: This diagram shows an atom's three main subatomic particles: protons and neutrons in the central nucleus, and electrons orbiting the nucleus.

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Isotope Noun

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[ahy-suh-tohp]

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Isotope

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Variants of a particular chemical element which differ in neutron number, but have the same number of protons.

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Example: Isotopes are versions of an element, like carbon, that have the same number of protons but different numbers of neutrons in their nucleus.

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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 has a net electrical charge due to the loss or gain of one or more electrons.

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Example: This image shows how a neutral sodium atom, with an equal number of protons and electrons, becomes a positive ion by losing one electron.

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Electric Charge Noun

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[ih-lek-trik chahrj]

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Electric Charge

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A fundamental physical property of matter that causes it to experience a force when placed in an electromagnetic field.

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Example: This diagram shows a neutral atom, where positive charges (+) in protons and negative charges (-) in electrons balance each other out.

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Atomic Mass Unit (amu) Noun

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[uh-tom-ik mas yoo-nit]

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Atomic Mass Unit (amu)

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A unit of mass used to express atomic and molecular weights, equal to one-twelfth of a carbon-12 atom's mass.

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Example: The number at the bottom of a periodic table tile, the atomic mass, represents the average mass of an element's atoms in atomic mass units (amu).