Chemistry

• Matter

  Anything that has mass and takes up space (can be solid (s), liquid (l) or gas (g))
• Properties


  Characteristics that describe a particular substance (density, colour, odour, taste, behaviour, melting point...)
• Chemistry

  The study if properties of matter and the changes matter undergoes
• Physical and Chemical Properties can help identify a substance
• Qualitative


  Cannot be measured (quality)
• Quantitative


  Can be measured numerically
• Element

  Something that cannot be broken down into a simpler substance
• Compound

  When two or more elements chemically combine
• Physical Change

  1. Change in the appearance or state of a substance that does not change the composition (no new substance is formed)

  2. State change

  3. Cutting

  4. Moulding

  5. Mixing colours together

  6. Dissolving
• Chemical Change

  When two or more materials react to create a new substance having properties different from the original. May be difficult or impossible to reverse
• Indicators for a Chemical Change

  • Colour change
  • Heat or light is given off/absorbed
  • Formation of a solid (precipitate)
  • Gas is given off (bubbles)
  • Odour change
• Atomic Number

  Number of protons and electrons in an atom
• Atomic Mass


  Mass of all protons and neutrons in an atom (amu)
• Mass Number

  Sum of the number of protons and neutrons in an atom
• Metals


  • Shiny lustre, malleable (hammered into sheets) and ductile (stretched into wires), conduct electricity, all are solid at room temperature except mercury
• Metals


  • Tin, aluminum, copper, gold, silver
• Non-metals


  • Dull, brittle, do not conduct electricity, insulators (except carbon)
• Non-metals


  • Nitrogen, Oxygen, Chlorine, Neon, Helium
• Metalloids

  Properties of both metals and non-metals
• Metalloids


  • Silicon, arsenic
• Reactive groups

  • Alkali Metals- most reactive metals
  • Alkaline Earth Metals
  • Halogens- most reactive non-metals. Found as compounds. Can be corrosive/harmful
  • Noble Gases(Inert gases)- stable and unreactive. Often glow. Don't combine
• Electrons


  Fill orbitals closest to the nucleus first with a maximum of 2 in the inner (1st) shell and 8 in the 2nd shell
• Isotopes


  Atoms of the same element with different atomic mass numbers (They will all have the same atomic number but different number of neutrons)
• Ions


  Charged particles. Atoms with unfilled outer electron shells become ions by lending or borrowing electrons when they bond with other atoms. Ions try to either totally fill the outer shell or eliminate it
• When naming compounds, the metals is ALWAYS first
• Ionic compounds


  • Pure substances formed when at least one metal and one non-metal combine. A metal atom transfers one or more electrons to a non-metal. The metal will end up with a positive charge and the non-metal will have a negative charge
  • High melting points
  • Conduct electricity
  • Crystals common due to strong bonds
  • Solids at room temperature
• Ion


  An atom or group of atoms that has become electrically charged through the loss or gain of electrons
• Salt formation: the salt formed will not have the same properties as the original elements
• Polyatomic Ions

  A group of atoms acting as one
• Molecule

  Two or more atoms joined together-can be the same or different
• Diatomic molecule

  Molecules made up of two of the same element (O2, N2, H2)
• Molecular Compound

  • When 2 or more non-metals combine. Atoms SHARE electrons (covalent bond)
  • Can be s, l, g
  • Low melting and boiling points
  • Poor conductors of electricity
• Chemical Reaction

  Reactant + Reactant - product(s)
• LAW OF CONSERVATION OF MASS- in a closed container the total mass of the reactants is equal to the mass of the products
• Exothermic reaction


  A chemical reaction that releases energy (heat, light, sound, mechanical)
• Endothermic reaction


  A chemical reaction that absorbs energy (heat)
• Combustion


  1. Burning- requires oxygen

  2. Products of combustion are carbon dioxide and water + other products
• Corrosion


  The oxidation (breaking down with exposure) of metals in the presence of air and moisture
• Cellular Respiration

  A chemical reaction that takes place in the cells in your body
• Types of Chemical Reactions

  • Synthesis: element OR compound + element OR compound
  • Double displacement: compound AB + compound CD -compound AD + compound CB