CHEMISTRY

• Mass #


  Number of protons + neutrons in the nucleus
• Atomic #

  Number of protons in the nucleus
• Protons


  Number of positively charged particles in the nucleus
• Electrons


  Number of negatively charged particles orbiting the nucleus
• Neutrons


  Number of neutral particles in the nucleus
• Element


  • Hydrogen (H)
  • Silver (Ag)
  • Neon (Ne)
• Electron configuration


  • Describes where electrons are located around the nucleus of an atom
• Writing electron configurations


  Follow the Aufbau principle - electrons occupy orbitals in order from lowest to highest energy level
• Energy level / shell


  Principal energy level where electrons reside
• Energy sub-level / sub-shell / orbital


  Specific region within an energy level where electrons can be found
• Bohr's Planetary Model


  n = energy level
• Electron configurations are important in determining the chemical properties of an atom</b>
• The outermost electrons determine an atom's ability to form bonds and its stability
• Components of electron configuration

  • Energy level / shell
  • Energy sub-level / sub-shell / orbital
  • Number of electrons in sub-level
• The Aufbau principle states that electrons occupy orbitals in order from lowest to highest energy level
• Bohr model of atom

  • Nitrogen (1s^2 2s^2 2p^3)
• Ions


  • Nitrogen (-3) (1s^2 2s^2 2p^6)
• Isotopes


  Atoms of the same element that have the same number of protons but different number of neutrons
• Atomic number (Z)


  The number of protons in the nucleus of an atom
• Mass number (A)


  The total number of protons and neutrons in the nucleus of an atom
• Isotopes of Hydrogen


  • Protium
  • Deuterium
  • Tritium
• Isotopes of Oxygen


  • Oxygen-16
  • Oxygen-17
  • Oxygen-18
• Isotopes of Carbon


  • Carbon-12
  • Carbon-13
  • Carbon-14
• Hydrogenation


  A process where molecular hydrogen is added to react with another compound to treat substances
• Tracer


  Used to investigate processes by labelling compounds
• Common isotopes and their uses

  • Protium for hydrogenation
  • Deuterium in fusion reactors
  • Tritium as fuel in nuclear fusion
  • Carbon-12 in human body
  • Carbon-13 as tracer
  • Carbon-14 in carbon dating
  • Oxygen-16 for respiration
  • Oxygen-17 as tracer
  • Oxygen-18 for fluorine-18 production
  • Sodium-24 to detect blood clots
  • Cobalt-60 to detect and treat cancer
  • Iodine-131 to detect thyroid function
  • Phosphorus-32 in fertilizers
  • Nitrogen-15 in fertilizers
  • Cesium-137 to kill bacteria
  • Fluorine-18 for diagnosis and treatment
  • Gallium-67 for diagnosis and treatment
• Bromine-79 has 35 protons, 35 electrons, and 44 neutrons
• Bromine-81 has 35 protons, 35 electrons, and 46 neutrons
• Carbon-13 has 6 protons, 6 electrons, and 7 neutrons
• Carbon-14 has 6 protons, 6 electrons, and 8 neutrons
• Molecules


  Made up of atoms that are chemically bonded together
• Molecules


  • Electrically neutral
  • Can be diatomic (two atoms)
  • Can be polyatomic (more than two atoms)
• Diatomic molecules


  • Cl2, N2, HCl, CO
• Polyatomic molecules


  • O3, H2O, NH3, CH4
• Ions


  Atoms or molecules that have a charge, meaning the number of protons is not equal to the number of electrons
• Atoms vs Ions


  • Atoms are neutral, containing the same number of protons and electrons
  • Atoms become ions when they lose or gain electrons, while the number of protons does not change
  • Neutral atoms (metals) can be turned into positively charged ions by removing electrons
  • Atoms (non-metals) that gain extra electrons become negatively charged
• Potassium atom has 19 protons, 19 electrons, and 0 neutrons. Potassium ion has 19 protons, 18 electrons, and 0 neutrons.
• Chlorine atom has 17 protons, 17 electrons, and 0 neutrons. Chlorine ion has 17 protons, 18 electrons, and 0 neutrons.
• Aluminium atom has 13 protons, 13 electrons, and 0 neutrons. Aluminium ion has 13 protons, 10 electrons, and 0 neutrons.
• Nitrogen atom has 7 protons, 7 electrons, and 0 neutrons. Nitrogen ion has 7 protons, 10 electrons, and 0 neutrons.