More Separation Techniques

• What is the purpose of crystallisation?

  To separate soluble salts from solution
• What is the first step in the crystallisation process?

  Heat the solution
• What happens when the solution cools during crystallisation?

  Crystals start to form
• What should you do after crystals form in the crystallisation process?

  Filter out crystals and leave to dry
• When is crystallisation particularly useful?

  For salts that decompose when heated
• What is the main principle of simple distillation?

  The part with the lowest boiling point evaporates first
• How does fractional distillation differ from simple distillation?

  It separates liquids based on their boiling points
• What happens to the liquid in fractional distillation?

  It rises up the fractionating column
• What is the role of the fractionating column in fractional distillation?

  To allow separation of liquids based on boiling points
• What is collected separately in fractional distillation?

  Fractions of the liquid mixture
• What are the components involved in fractional distillation?

  • Fractionating column
  • Glass rods
  • Heat source
  • Condenser
  • Mixture of liquids
  • Fractions collected separately
• Who proposed the Plum pudding model of the atom?

  J.J. Thomson
• What did Niels Bohr contribute to atomic theory?

  Proposed electrons orbiting the nucleus
• What are the energy levels in an atom called?

  Electron shells
• How many electron shells are typically mentioned in basic atomic theory?

  Three
• What is the term for negatively charged particles in an atom?

  Electrons
• What is the charge of protons in an atom?

  Positive
• What is the charge of neutrons in an atom?

  Neutral
• What is the nucleus of an atom composed of?

  Protons and neutrons
• What is the overall charge of an atom?

  Neutral