DENSITY MTRLS, INT ENERG,CHANGES STATE,SLH, PRTCL MOTION GAS

• What does the particle model of matter state about all substances?

  Everything is made up of lots of tiny particles.
• How does the particle model explain density?

  Density relates the mass of a substance to how much space it takes up.
• What is the formula for density?

  Density (kg/m³) = mass (kg) / volume (m³).
• What does density indicate about particles in a material?

  It shows how tightly packed the particles are and how they are arranged.
• How does the density of a material change when it is compressed?

  The particles move closer together, increasing the density.
• What is the state of matter where particles vibrate about fixed positions?

  Solids.
• Why is the density generally highest in solids?

  Because the particles are closely packed together.
• How do particles behave in liquids compared to solids?

  Particles in liquids have more energy and move in random directions at low speeds.
• What characterizes gas particles compared to those in solids and liquids?

  Gas particles have high speeds and are free to move in random directions.
• What is the first step to find the density of a solid object?

  Use a balance to measure the mass.
• What are the steps to find the density of a solid object?

  1. Measure the mass using a balance.
  2. For a regular solid, measure length, width, and height, then calculate volume.
  3. For an irregular solid, submerge it in a eureka can to find the volume of water displaced.
  4. Use the formula to find density.
• How do you find the density of a liquid?

  Measure the mass of the liquid in a measuring cylinder and calculate density.
• What are the steps to find the density of a liquid?

  1. Zero the balance with a measuring cylinder.
  2. Pour 10 ml of liquid, record mass.
  3. Repeat until full, recording total volume and mass.
  4. Calculate density for each measurement and take an average.
• What is the formula for the volume of a cube?

  Volume = length × width × height.
• What is internal energy in a system?

  • Energy stored by particles in a system.
  • Includes kinetic energy (motion) and potential energy (position).
  • Total energy is the sum of kinetic and potential energy stores.
• How does heating a system affect its internal energy?

  Heating transfers energy to particles, increasing their kinetic energy and internal energy.
• What happens to particles when a substance is heated enough to change state?

  Particles gain enough energy to break the bonds holding them together.
• What are the changes of state for substances?

  • Solid to liquid: melting
  • Liquid to gas: boiling or evaporating
  • Gas to liquid: condensing
  • Liquid to solid: freezing
  • Solid to gas: sublimating
• What is a physical change in terms of state change?

  A physical change means the substance remains the same, just in a different form.
• What happens to the number of particles during a change of state?

  The number of particles remains the same; they are just arranged differently.
• What is latent heat?

  Latent heat is the energy needed to change the state of a substance without changing its temperature.
• What is the specific latent heat of fusion?

  It is the energy needed to change a substance from solid to liquid or vice versa.
• What is the specific latent heat of vaporisation?

  It is the energy needed to change a substance from liquid to gas or vice versa.
• How do you calculate the energy needed to change the state of a substance?

  Energy (E) = Mass (m) × Specific Latent Heat (L).
• How does temperature relate to the average energy in the kinetic energy stores of gas particles?

  The higher the temperature, the higher the average energy and speed of the particles.
• What happens when gas particles collide with the walls of their container?

  They exert a force, creating pressure on the walls.
• How does increasing the temperature of a gas affect its pressure if the volume is constant?

  Increasing temperature increases the speed of particles, thus increasing pressure.
• What happens to gas pressure when the volume of the gas increases at constant temperature?

  The gas pressure decreases as the particles hit the walls less often.
• What is the relationship between pressure and volume for a gas of fixed mass at constant temperature?

  Pressure and volume are inversely proportional; as one increases, the other decreases.
• What happens to a balloon when it rises in the atmosphere?

  The balloon expands due to decreasing atmospheric pressure with height.
• How does doing work on a gas affect its temperature?

  Doing work on a gas increases its internal energy and can raise its temperature.
• What happens to the temperature of a gas when you use a bike pump?

  The temperature of the gas increases as work is done on it.