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
• Substances are made of atoms
• Element


  Different types of atoms represented in the periodic table by a symbol
• Compound


  Substance that contains two or more different types of atoms chemically bonded together
• If there's no number after a symbol, there's an invisible 1
• Chemical reaction


  Atoms change what they're bonded to and how they're bonded
• Word equation


  Representation of a reaction using words
• Chemical equation


  Representation of a reaction using symbols
• Atoms are not created or destroyed in any chemical reaction, so the same number of each type of atom must be on both sides of the equation</b>
• Balancing chemical equations


  Start with atoms only in compounds, then balance remaining atoms by putting numbers in front of elements/compounds
• Mixture


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


  Mixture of a solute (dissolved substance) and a solvent
• Separation techniques


  1. Filtration

  2. Crystallization

  3. Distillation
• Physical process


  No new substances are being made
• States of matter


  • Solid
  • Liquid
  • Gas
• Gases


  • Particles are far apart and move randomly, have the most energy and can be compressed
• To melt or evaporate a substance


  Energy, usually in the form of heat, must be supplied to overcome the electrostatic forces of attraction between the particles
• Breaking bonds does not occur in physical changes, only in chemical reactions
• Atom models


  • JJ Thompson's plum pudding model
  • Rutherford's discovery of the nucleus and mostly empty space
  • Bohr's discovery of electron shells/orbitals
  • Chadwick's discovery of neutrons
• Protons


  Positive charges in the nucleus
• Electrons


  Negative charges orbiting the nucleus
• Neutrons


  Neutral charges in the nucleus
• 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


  Organizes elements based on their properties
• Development of the periodic table

  1. Ordered by atomic weight

  2. Grouped by properties (Mendeleev)

  3. Gaps predicted and later filled
• Electron configuration


  Arrangement of electrons in shells/orbitals around the nucleus
• Periodic table sections


  • Metals (left of staircase)
  • Nonmetals (right of staircase)
  • Transition metals
• Group


  Column in the periodic table, indicates number of outer shell electrons
• Group names


  • Group 1 (alkali metals)
  • Group 7 (halogens)
  • Group 0 (noble gases)
• Alkali metals


  • Have one outer electron which is readily donated
  • Reactivity increases down the group
• Halogens


  • Have seven outer electrons, need one more to be full
  • Reactivity decreases down the group
  • Boiling points increase down the group
• Noble gases


  • Have full or empty outer shells, very unreactive
• Ion


  Atom that has gained or lost electrons, no longer electrically neutral
• Ion charges


  • Group 1 (+1)
  • Group 2 (+2)
  • Group 7 (-1)
  • Group 6 (-2)
  • Transition metals (variable)
• Metallic bonding


  • Lattice of metal ions with delocalized electrons, good conductors
• Ionic bonding


  Transfer of electrons between a metal and a nonmetal to form ions
• Drawing ionic compound structures

  1. Use dot and cross diagrams to show electron transfer

  2. Ions must balance to form a neutral compound