Particles + Mixtures

• What are the three states of matter?

  Solid, liquid, and gas
• How does the state of matter depend on particle arrangement?

  It depends on arrangement and energy of particles
• What is the characteristic of solids?

  Fixed shape and volume
• How do particles behave in liquids?

  They slide past each other
• What is a characteristic of gases?

  No fixed shape or volume
• What happens during changes of state?

  Energy changes occur during state changes
• What are the five changes of state?

  Melting, freezing, evaporation, condensation, sublimation
• What is diffusion?

  Movement from high to low concentration
• Why is diffusion faster in gases than in liquids?

  Due to weaker intermolecular forces in gases
• What is Brownian motion?

  Random movement of particles in a fluid
• What is a solute?

  Substance that dissolves
• What is a solvent?

  Substance in which solute dissolves
• What is a solution?

  Mixture of solute and solvent
• What does saturation refer to?

  Maximum solute that can dissolve
• What is the method to investigate solubility?

  1. Heat water to a known temperature
  2. Add solute until no more dissolves
  3. Record mass of dissolved solute and temperature
  4. Plot a solubility curve (solubility vs. temperature)
• How does solubility change with temperature for most solids?

  Solubility increases with temperature
• What does the nucleus of an atom contain?

  Protons and neutrons
• What are electrons?

  Negatively charged particles orbiting the nucleus
• What is the atomic number (Z)?

  Number of protons in an atom
• What is the mass number (A)?

  Total number of protons and neutrons
• When are atoms considered neutral?

  When protons equal electrons
• What are isotopes?

  Atoms with different numbers of neutrons
• How do isotopes differ from each other?

  They have different mass numbers
• What is relative atomic mass?

  Weighted average of isotopes based on abundances
• What is an element?

  Substance made of one type of atom
• What is a compound?

  Substance formed by chemical combination of elements
• What is a mixture?

  Physical combination of substances, not chemically bonded
• How can mixtures be separated?

  By physical methods like filtration
• What is filtration used for?

  To separate an insoluble solid from a liquid
• What equipment is used in filtration?

  Filter paper, funnel, beaker
• What is the process of crystallisation?

  1. Heat the solution to evaporate water
  2. Leave concentrated solution to cool
  3. Crystals form as solubility decreases
• What is chromatography used for?

  To separate substances based on solubility
• What does a higher Rf value indicate?

  Higher solubility of the substance
• What are applications of chromatography?

  Identifying dyes in ink or mixtures
• What is simple distillation used for?

  To separate a liquid from a solution
• What is fractional distillation used for?

  To separate liquids with different boiling points
• What is an example of fractional distillation?

  Separating ethanol from water
• What is another example of fractional distillation?

  Separating crude oil fractions