Chemistry Paper 1 AQA

• Atom

  Something that can't be broken down or split into its constituents or smaller bits by chemical means
• Compound

  Two or more types of atoms chemically bonded together
• Mixture

  Different types of atoms or compounds not chemically bonded together
• Chromatography

  Filter paper with a dot of the mixture about a centimeter above the water line, the filter paper is dipped in water, the water gets drawn up the paper due to capillary action and drags particles of the mixture with it, the particles that end up the highest on the paper are the lighter particles
• RF value

  Retention factor, calculated by doing how far the solute has gone up the paper divided by how far the solvent has gone
• Filtration

  Removes insoluble particles like sand from water, using filter paper in a funnel
• Distillation

  Separates a solid from a solvent like salt from water, by heating the mixture or solution so the water evaporates and is then re-condensed using a condenser tube
• Nucleus

  Contains neutrons and protons in the middle of an atom
• Electrons

  Orbit around the outside of the nucleus
• Protons

  Have a charge of +1
• Electrons

  Have a charge of -1
• Neutrons

  Have no charge
• Atoms have to have the same number of protons as electrons so they are neutral
• Ion

  An atom that has lost or gained electrons, resulting in a positive or negative charge
• Columns/Groups in the periodic table

  • 1 2 (gap) 3 4 5 6 7 8 or 0
• Column/Group


  Tells you how many electrons are in the outer shell of an element
• Period


  Tells you how many shells of electrons an element has
• Types of elements

  • Metals (to the left of the staircase)
  • Nonmetals (to the right of the staircase)
• Alkali metals


  Group 1, get more reactive as you go down the group
• Halogens

  Group 7, get less reactive as you go down the group
• Noble gases

  Group 8 or 0, very unreactive
• Atomic number


  Number of protons in the nucleus
• Mass number

  Number of protons plus neutrons in the nucleus
• Electron shell filling

  2 8 8 2
• We only really care about the first 20 elements on the periodic table, up to calcium
• Chlorine

  Atomic number 17, has 17 protons and 17 electrons, with 7 electrons in the outer shell
• Ionic bonding

  Metals bond to nonmetals by donating electrons, forming positive and negative ions
• Ionic compound

  • Magnesium chloride (MgCl2)
• Dot and cross diagram for ionic bonding

  Metal has an empty outer shell, nonmetal has crosses for electrons and gains the metal's electron(s)
• Properties of ionic compounds

  • High melting and boiling points, soluble in water, can conduct electricity when molten or in solution
• Covalent bonding

  Nonmetals bond to other nonmetals by sharing electrons to achieve a full outer shell
• Simple covalent compound

  • Methane (CH4)
• Dot and cross diagram for covalent bonding

  Draw the outer shells and show the shared electron pairs in the covalent bonds
• Covalent compounds

  • Carbon dioxide (CO2) - has double covalent bonds
• Metallic bonding

  Atoms form a lattice with delocalized electrons surrounding the positive ions
• Polymer


  Long chain formed by joining many individual monomer molecules together
• Polymer

  • Polyethylene (from ethene monomers)
• To make a polymer, high pressure and a catalyst are needed to force the monomers together
• Oxidation

  A metal reacts with oxygen to form a metal oxide
• Acid-base reaction

  An acid reacts with a metal hydroxide to form a salt and water (neutralization)