Paper 1

• This is good for higher and Foundation Tier double combined Trilogy and triple separate chemistry that's topics 1 to five atoms bonding quantitative chemistry and chemical and energy changes
• If there's no number after a symbol there's an invisible one there
• Balancing chemical equations


  1. Start balancing atoms that are only in compounds

  2. Can't change small numbers as that would change the compound

  3. Put numbers in front of elements or compounds to multiply them up

  4. Finish balancing elements that are not in compounds
• Mixture


  Any combination of any different types of elements and compounds that aren't chemically bonded together
• Solution


  A mixture of a solute dissolved in a solvent
• Separating mixtures


  1. Filtration for large insoluble particles

  2. Crystallization to leave solute behind after evaporating solvent

  3. Distillation to separate liquids with different boiling points
• Physical processes


  • No new substances are being made
• States of matter


  Solid - particles vibrate around fixed positions

  Liquid - particles can move past each other

  Gas - particles are far apart and move randomly
• Melting and evaporation are physical changes, not chemical reactions
• Atomic models


  • JJ Thompson - plum pudding model

  Rutherford - positive nucleus with electrons orbiting

  Bohr - electrons in shells/orbitals

  Chadwick - nucleus contains protons and neutrons
• Atomic number


  Number of protons in the nucleus
• Mass number


  Number of protons and neutrons in the nucleus
• Isotopes


  Atoms of the same element with different numbers of neutrons
• Relative abundance


  Percentage of each isotope in a sample
• Periodic table development


  Ordered by atomic weight, then grouped by properties, gaps predicted and later filled
• Electron configuration


  Electrons fill up shells/orbitals from the inside
• Periodic table sections


  • Metals - left of staircase

  Non-metals - right of staircase

  Transition metals
• Rate of reaction


  How quickly a reaction happens
• Group


  Column in periodic table, tells number of outer shell electrons
• Mean rate


  The rate could be changing over the time you measure, but this is true for any measurement over time
• Group 1 - alkali metals


  • Have 1 outer electron, readily donate it

  Reactivity increases down group
• Experiment to measure rate of reaction

  1. Reacting hydrochloric acid and sodium thiosulfate in a conical flask

  2. Measuring the time taken for the solution to become cloudy and obscure a cross underneath

  3. Repeating at different temperatures
• Group 7 - halogens


  • Have 7 outer electrons, need 1 more to fill shell

  Reactivity decreases down group
• As temperature increases


  The time taken for the reaction decreases
• Group 0 - noble gases

  • Have full outer shells, very unreactive
• Experiment to measure rate of reaction

  1. Measuring the volume of gas produced using a gas syringe

  2. Plotting a graph with quantity on y-axis and time on x-axis

  3. Drawing a tangent to find the rate at any point
• Ion


  Atom that has gained or lost electrons, no longer neutral
• Factors that increase rate of reaction

  • Increasing concentration of reactants
  • Increasing pressure of gas reactants
  • Increasing surface area of solid reactants
  • Increasing temperature
  • Adding a catalyst
• Ionic bonding


  • Metal atoms donate electrons, non-metal atoms accept them

  Ionic compounds have high melting/boiling points and can conduct electricity when molten or dissolved
• Activation energy


  The energy needed for particles to collide successfully and react
• Covalent bonding


  Non-metal atoms share electrons to fill outer shells
• Reversible reaction


  Reactions where the products can reform the original reactants
• Simple molecular structures


  • Individual molecules with relatively low boiling points
• Equilibrium


  The point where the rates of the forward and reverse reactions are equal, so there is no overall change
• Giant covalent structures


  • Continuous networks of covalent bonds, very high melting points (e.g. diamond, graphite)
• Increasing pressure


  Favours the forward reaction in a reversible reaction
• Allotropes


  Different structural forms of the same element (e.g. carbon)
• Increasing temperature


  Favours the endothermic (reverse) reaction in a reversible reaction
• In a reversible reaction, if the forward reaction is exothermic, the reverse reaction must be endothermic
• Nanoparticles


  Structures between 100-2500 nm in size, high surface area to volume ratio