Science test revision

• What is crystallisation? 


  Seperating soluble solids from a solution (dissolved solids out a liquid)
• Crystallisation step 1-


  Stir solid to dissolve
• Crystallisation step 2-


  Heat solution to evaporate most of solvent
• Crystallisation step 3-


  Cool solution to obtain crystals
• Crystallisation step 4-


  Filter solution to obtain crystals
• What is fraction distillation?


  The separation of a mixture into its component parts or fraction
• What is the purpose of a thermometer in a laboratory setup?

  To measure temperature
• What is a component of a distillation apparatus?

  Fractionating column
• What type of flask is commonly used in distillation?

  Round-bottom flask
• Why is water used in distillation setups?

  It acts as a coolant in the condenser
• What is the function of a condenser in a distillation apparatus?

  To cool and condense vapor back to liquid
• What are the main components of a distillation apparatus?

  • Thermometer
  • Fractionating column
  • Round-bottom flask
  • Condenser
  • Water in and out
• What is the role of the water in the condenser?

  To absorb heat from the vapor
• What is the typical shape of a round-bottom flask?

  Curved and spherical
• How does a fractionating column improve distillation efficiency?

  It provides more surface area for vapor condensation
• How do the components of a distillation apparatus work together?

  They facilitate the separation of liquid mixtures
• What are isotopes?

  Atoms with same protons, different neutrons
• What is a solute?

  A solid that can dissolve in a solvent
• What is a solvent?

  A substance that dissolves in a solute
• What is a solution?

  A mixture formed after a solvent dissolves in a solute
• What are the charges, masses, and locations of protons, neutrons, and electrons?

  • Proton: Charge +1, Mass 1, Location nucleus
  • Neutron: Charge 0, Mass 1, Location nucleus
  • Electron: Charge -1, Mass very small, Location orbiting nucleus
• How do you determine the number of protons in an atom?

  It equals the atomic number
• How do you determine the number of electrons in an atom?

  It equals the number of protons
• How do you calculate the mass of an atom?

  Mass = number of neutrons + protons
• How do you find the number of neutrons in an atom?

  Number of neutrons = mass number - atomic number
• What element's electron structure is mentioned?

  Lithium
• What is the atom number of Lithium?

  • Atomic number: 3