particle model of matter

• What are the three states of matter?

  Solid, liquid, gas
• What are the characteristics of solids?

  • Strong forces of attraction
  • Fixed, regular arrangement of particles
  • Particles vibrate in fixed positions
  • High density due to closely packed particles
• What are the characteristics of liquids?

  • Weaker forces of attraction
  • Particles close together but can move past each other
  • More energy than solids
  • Move in random directions at low speeds
  • Generally less dense than solids
• What are the characteristics of gases?

  • Almost no forces of attraction
  • Most energy among the states
  • Free to move in random directions at high speeds
  • Low densities
• What does density measure?

  How compact a substance is
• What is the formula for density?

  Density = mass divided by volume
• What is internal energy?

  • Energy stored by particles in a system
  • Particles vibrate/move, having kinetic energy
  • Total energy in kinetic energy stores of particles
• How does heating a system affect its internal energy?

  It transfers energy to the particles
• What can heating a system lead to?

  Temperature change or change in state
• What is a change of state?

  • A physical change
  • Mass is conserved
  • Number of particles does not change
  • Only their arrangement changes
• What is specific latent heat?

  Energy needed to change 1kg of substance
• What is the formula for energy related to specific latent heat?

  Energy = mass x specific latent heat
• What does the particle model of matter density indicate?

  How compact mass is for a material
• Why does a cup of iron have a higher density than a cup of cream?

  Iron has a much higher mass than cream
• In what units do we measure density?

  Kilograms per cubic meter
• What is the equation for density?

  Density = mass / volume
• What symbol is used for density?

  The Greek letter rho
• What factors affect density?

  Particle composition and packing density
• Why is water vapor less dense than liquid water?

  Water vapor particles are more spread out
• How do you find the density of a regular object?

  Calculate volume and measure mass
• How is the volume of a cuboid calculated?

  Length × width × height
• Why might a ruler not be accurate for small measurements?

  Its resolution is likely 1 mm
• What tool is better than a ruler for measuring small lengths?

  Vernier calipers
• What is the resolution of vernier calipers?

  0.1 mm
• What tool is used for very thin objects like wires?

  Micrometer
• What is the resolution of a micrometer?

  0.01 mm
• How do you find the volume of an irregular object?

  Use water displacement method
• What is the principle behind the water displacement method?

  It measures the volume of displaced water
• What happens to particles in a solid state of matter?

  They vibrate around fixed positions
• How do particles behave in a liquid state?

  They are close but can move past each other
• What characterizes gas particles?

  They are far apart and move randomly
• What changes occur during an increase in temperature?

  Increase in kinetic energy of particles
• What is the equation for increase in thermal energy?

  ΔE = mcΔT
• When is the specific heat capacity equation used?

  For an increase in kinetic energy of particles
• What is the equation for energy needed to change state?

  ΔE = mL
• How does increased gas pressure occur?

  Particles collide with container walls more forcefully
• What must be supplied to melt a solid or evaporate a liquid?

  Energy, usually in the form of heat
• What happens to the temperature of ice when heat is supplied?

  It increases until melting point is reached
• What occurs at the melting point of ice?

  Temperature remains constant until melted
• What happens to temperature when a substance changes state?

  Temperature remains constant during the change