C1

• What is the total number of protons and neutrons in an atom called?

  Mass number
• What does the atomic number represent?

  Number of protons in an atom
• What defines an element?

  Substances made up of atoms with the same atomic number
• What are isotopes?

  Atoms with the same number of protons but different numbers of neutrons
• What is the relative atomic mass?

  The average mass number for an element
• What are the components of an atom and their relative properties?

  • Proton: Relative mass = 1, Charge = +1
  • Neutron: Relative mass = 1, Charge = 0
  • Electron: Relative mass = very small, Charge = -1
• What is a compound?

  A substance formed from two or more elements chemically bonded together in fixed proportions
• What is a molecule?

  A particle containing two or more non-metal atoms bonded covalently
• What does a chemical formula show?

  The proportion of atoms of each element in a compound
• What is a chemical equation?

  It shows the overall change in a reaction
• What is the purpose of balancing a chemical equation?

  To ensure the same number of each atom on both sides
• What is a mixture?

  Substances made up of different elements or compounds that aren't chemically bonded
• How can mixtures be separated?

  By physical methods that don't involve chemical reactions
• What is the process of paper chromatography?

  1. Spot of mixture placed on filter paper
  2. Solvent moves up the paper
  3. Components separate based on solubility
  4. Insoluble components remain on the baseline
• What is filtration used for?

  To separate insoluble solids from liquids and solutions
• What is evaporation used for?

  To separate soluble salts from a solution
• What is crystallisation?

  A method to separate soluble salts from a solution by cooling
• What is simple distillation used for?

  To separate liquids with different boiling points
• How does fractional distillation differ from simple distillation?

  It can separate liquids with similar boiling points
• What are the key models of atomic structure in history?

  • Plum pudding model: Positive charge with negative electrons
  • Nuclear model: Mass concentrated in a nucleus with electrons in a cloud
  • Bohr model: Electrons orbit nucleus in fixed shells
• What is the electronic structure of an atom?

  Electrons occupy shells or energy levels
• How do electrons fill the shells of an atom?

  They fill each shell up before occupying a new one, starting with the lowest energy
• What is Mendeleev's Table of Elements based on?

  Grouping elements using their properties
• What does the modern periodic table order elements by?

  Increasing atomic number
• What do the group and period numbers in the periodic table indicate?

  Group number = number of outer shell electrons; Period number = number of electron shells
• What are the properties of metals?

  Shiny, strong, malleable, good conductors
• What are the properties of non-metals?

  Dull, brittle, poor conductors
• What are transition metals?

  Metals in the center of the periodic table with unique properties
• What happens to the reactivity of alkali metals as you go down Group 1?

  Reactivity increases
• What are the properties of Group 1 metals?

  More reactive, less dense, softer, lower melting points
• What are Group 0 elements known for?

  They are non-metals with full outer shells and are unreactive
• What happens to the boiling point of Group 0 elements as you go down the group?

  Boiling point increases
• What are Group 7 elements known as?

  Halogens
• How do halogens fill their outer shell?

  By sharing electrons or gaining an electron
• What is the result of a more reactive halogen displacing a less reactive one?

  The more reactive halogen takes the place of the less reactive one