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Atomic Theory definitions

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  • Atomic Theory
    A scientific theory that matter is composed of discrete units called atoms.
  • Atom
    The smallest unit of matter that retains the identity of a chemical element.
  • Isotope
    Atoms of the same element with the same atomic number but different mass numbers.
  • Subatomic Particles
    Particles that are smaller than an atom, including protons, neutrons, and electrons.
  • Conservation of Mass
    A principle stating that mass cannot be created or destroyed in a chemical reaction.
  • Element
    A substance consisting of atoms which all have the same number of protons.
  • Compound
    A substance formed when two or more chemical elements are chemically bonded together.
  • Mass Number
    The total number of protons and neutrons in an atomic nucleus.
  • Chemical Reaction
    A process that involves rearrangement of the molecular or ionic structure of a substance.
  • Proton
    A subatomic particle found in the nucleus of every atom, carrying a positive charge.
  • Neutron
    A subatomic particle found in the nucleus of atoms, having no electric charge.
  • Electron
    A subatomic particle with a negative charge, found in all atoms and acting as the primary carrier of electricity.
  • Molecular Structure
    The arrangement of atoms within a molecule.
  • Carbon
    A chemical element with symbol C and atomic number 6, known for its various allotropes.
  • Dalton's Postulates
    A set of principles proposed by John Dalton to describe the nature of atoms and matter.