Particle Model of Matter

• specific heat capacity definition?

  The specific heat capacity of a substance is the amount of thermal energy needed to increase the temperature of 1 kg of the substance by 1°C.
• specific latent heat definition?

  The specific latent heat of a substance is the amount of energy needed to change the state of 1 kg of the substance without changing its temperature.
• specific heat capacity equation

  
• specific latent heat equation

  
• specific heat capacity vs latent difference

  Although the definition of specific heat capacity seems very similar to the definition of specific latent heat, there is one key difference. Specific heat = energy needed to change one kilogram of a material by 1°C. Latent heat = energy needed to change the state (gas, liquid, solid) of one kilogram of material.
• for this equation you need to work out the mass. You do energy / specific heat capacity x change in temperature. 877.8 /4180 x 30=6.3

  
• all materials increase volume with an increase in temperature
• all substances density decreases as temperature

  increases
• Explain why it takes longer to heat up a large mass of water than a small mass, even if both have the same temperature increase.


  It takes longer to heat a larger mass of water because the energy required to increase the temperature depends on the mass. A larger mass has more particles, which need more energy to increase their temperature by the same amount. The formula for energy required to change temperature is Q = mc\Delta T, where the mass m directly affects the energy needed.
• explain the difference between specific heat capacity & specific latent heat.

  • specific heat capacity = energy required to change temperature of 1 kg of a substance by 1°C. (1)
  • specific latent heat = energy required to change state of 1 kg of a substance without changing its temperature. (1)
•  What are the three states of matter?

  Solid, liquid, gas.
• What are the two types of latent heat?

  A: Latent heat of fusion (solid ↔ liquid) and Latent heat of vaporisation (liquid ↔ gas).
• Why does temperature stay constant during a change of state?

  Energy is used to break or form bonds instead of raising temperature.
• What is gas pressure?

  The force exerted by gas particles colliding with the walls of a container.
• What happens to gas pressure if volume is decreased?

  Pressure increases, as particles collide more frequently with container walls.
• What is Boyle’s Law?

  Pressure × volume = constant (if temperature is constant).
•  What is internal energy?

  The total kinetic and potential energy of all particles in a system.
• How does heating affect internal energy?

  •Increases kinetic energy of particles, raising temperature.

  •If enough energy is added, it can cause a state change (solid → liquid → gas).
• What happens to potential energy during a state change?

  •Increases as particles move apart (melting/boiling).

  •Decreases as particles come together (freezing/condensing).