chemistry paper 1 gcse

• 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, the different types of atoms are represented in the periodic table by a symbol
• Compound


  A substance that contains two or more different types of atoms chemically bonded together
• Atoms change what they're bonded to and how they're bonded through chemical reactions
• Word equation


  A way to represent a chemical reaction
• Chemical equation


  A way to represent a chemical reaction using symbols
• Balancing a chemical equation

  1. Start with atoms that are only in compounds

  2. Balance the number of atoms on both sides
• Mixture


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


  • Air
  • Salt water
• Solution


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


  1. Filtration

  2. Crystallization

  3. Distillation
• Physical processes


  • No new substances are being made
• States of matter


  • Solid
  • Liquid
  • Gas
• Melting and evaporation are physical changes, not chemical reactions
• State symbols


  (s) for solid

  (l) for liquid

  (g) for gas

  (aq) for aqueous (dissolved in water)
• Atom models


  • JJ Thompson's plum pudding model

  Rutherford's discovery of the nucleus and empty space

  Bohr's discovery of electron shells
• Protons


  Positive charges in the nucleus
• Neutrons


  Neutral charges in the nucleus
• Electrons


  Negative charges orbiting 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


  The percentage of each isotope in a sample
• The periodic table was originally ordered by atomic weight, then later by properties
• Electron configuration


  The arrangement of electrons in shells around the nucleus
• Sections of the periodic table

  • Metals

  Non-metals

  Transition metals
• Group


  The column an atom is in on the periodic table
• Groups


  • Group 1 (alkali metals)

  Group 7 (halogens)

  Group 0 (noble gases)
• Ion


  An atom that has gained or lost electrons, giving it a positive or negative charge
• Transition metals can form ions with different charges
• Metallic bonding


  Bonding in metals where a lattice of positive ions is surrounded by delocalized electrons
• Ionic bonding


  Bonding between a metal and a non-metal where electrons are transferred
• Covalent bonding


  Bonding between non-metals where electrons are shared
• Molecular ions


  Ions made up of more than one atom
• Simple molecular/covalent structures


  Individual molecules that can mix together
• Giant covalent structures


  Structures where covalent bonds extend in all directions, forming one giant molecule
• Allotropes


  Different forms of the same element, like diamond and graphite
• Nanoparticles are between 100-2500 nm in size, smaller than dust particles
• The total mass of substances is conserved in a chemical reaction
• Mole


  A specific number of atoms or molecules used to compare amounts of substances