GCSE CHEMISTRY PAPER 1 FLASHCARDS

• 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 representation of a chemical reaction using words
• Chemical equation


  A representation of a chemical reaction using symbols
• Balancing a chemical equation

  1. Start with atoms that are only in compounds

  2. Balance atoms that are only on one side

  3. Use numbers in front of elements or compounds to multiply them up
• Mixture


  Any combination of any 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)
• Discovered atoms are made of positive and negative charges


  JJ Thompson
• Discovered the positive charge is in a small nucleus and electrons orbit relatively far away


  Ernest Rutherford
• Discovered electrons exist in shells or orbitals

  Niels Bohr
• Discovered the nucleus contains neutral charges called neutrons


  James Chadwick
• Atomic number


  The number of protons in the nucleus
• Mass number


  The total 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 atomic number and properties
• Electron configuration


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

  • Metals
  • Non-metals
• Group


  The column an atom is in on the periodic table, indicates the number of electrons in the outer shell
• Groups


  • Group 1 (alkali metals)

  Group 7 (halogens)

  Group 0 (noble gases)
• Ion


  An atom that has gained or lost electrons, no longer electrically neutral
• Transition metals


  Can form ions with different charges
• Metallic bonding


  Bonding in metals, a lattice of positive ions with delocalized electrons
• Ionic bonding


  Bonding between a metal and a non-metal, where the metal donates electrons to the non-metal
• Covalent bonding


  Bonding between non-metals, where electrons are shared
• Molecular ion


  An ion formed from a group of atoms, e.g. hydroxide ion (OH-)
• Salt


  Any ionic compound, not just sodium chloride
• Simple molecular/covalent structures


  Individual molecules that can mix together, have low boiling points
• Giant covalent structures


  One continuous network of covalent bonds, e.g. diamond and graphite
• Allotropes


  Different structural forms of the same element, e.g. diamond and graphite
• Nanoparticles


  Structures between 100-2500 nm in size
• Surface area to volume ratio


  Ratio of a particle's surface area to its volume, increases as particle size decreases
• Relative formula mass


  The sum of the relative atomic masses of the atoms in a compound