3. ATOMIC STRUCTURE Glossary GCSE EDEXCEL CHEMISTRY

Glossary
  1. abundance
    How much is available of substance.
  2. atom
    The smallest part of an element that can exist.
  3. atomic number
    The number of protons in the nucleus of an atom. Also called the proton number.
  4. charge (electrical)
    An imbalance of electrons and protons in a material. An excess of electrons results in negative charge, a deficit of electrons results in positive charge.
  5. electron
    Subatomic particle, with a negative charge and a negligible mass relative to protons and neutrons.
  6. element
    A substance made of one type of atom only.
  7. isotope
    Atoms of an element with the same number of protons and electrons but different numbers of neutrons.
  8. mass
    The amount of matter an object contains. Mass is measured in kilograms (kg) or grams (g).
  9. mass number
    The number of protons and neutrons found in the nucleus of an atom.
  10. neutral atom
    An atom in which the number of protons and electrons is the same.
  11. neutron
    Uncharged subatomic particle, with a mass of 1 relative to a proton. The relative charge of a neutron is 0.
  12. nuclei
    Nuclei is the plural of nucleus. The nucleus is the central part of an atom. It contains protons and neutrons, and has most of the mass of the atom.
  13. nucleus
    The central part of an atom. It contains protons and neutrons, and has most of the mass of the atom. The plural of nucleus is nuclei.
  14. particle
    A general term for a small piece of matter. For example, protons, neutrons, electrons, atoms, ions or molecules.
  15. properties
    The characteristics of something. In chemistry, chemical properties include the reactions a substance can take part in. Physical properties include colour and boiling point.
  16. proton
    Subatomic particle with a positive charge and a relative mass of 1. The relative charge of a proton is +1.
  17. relative atomic mass
    The mean relative mass of the atoms of the different isotopes in an element. It is the number of times heavier an atom is than one-twelfth of a carbon-12 atom.
  18. relative mass
    The relative mass is the number of times heavier a particle is, compared to another.
  19. subatomic particle
    Objects found in atoms, including protons, neutrons and electrons