3.2.2 Internal Energy

• What is internal energy in the context of particles?

  Total kinetic and potential energy
• Kinetic energy is the energy of motion
• Potential energy arises from forces between particles.
• Why is internal energy crucial for understanding phase changes?

  Affects thermal properties
• Molecular vibrations, translations, and rotations contribute to kinetic energy.
• Which type of energy is associated with the position or interaction of particles?

  Potential energy
• Potential energy arises from forces between particles
• How does kinetic energy change during boiling?

  Increases
• Potential energy remains constant during heating within a phase.
• What happens to internal energy during melting?

  Increases
• During freezing, kinetic energy decreases
• Condensation occurs when a gas releases heat.
• Give an example of kinetic energy contributing to internal energy.

  Vibrating atoms in a solid
• Relation to internal energy: Potential energy increases during phase changes
• What is the key difference between kinetic and potential energy of particles?

  Source and manifestation
• Kinetic energy is the energy of motion
• Kinetic energy increases with temperature.
• Potential energy arises from the position or interaction between particles
• Potential energy remains constant during heating within a phase.
• What is the source of kinetic energy?

  Motion of particles
• How does kinetic energy contribute to internal energy?

  Molecular vibrations, translations, rotations
• What is the source of potential energy?

  Position or interaction of particles
• Arrange the following phase changes in order based on heat exchange and energy changes:

  1️⃣ Melting: Absorbs heat, kinetic energy increases, potential energy decreases

  2️⃣ Boiling: Absorbs heat, kinetic energy increases, potential energy decreases

  3️⃣ Freezing: Releases heat, kinetic energy decreases, potential energy increases

  4️⃣ Condensation: Releases heat, kinetic energy decreases, potential energy increases
• During melting, a solid absorbs heat and its kinetic energy increases.
• During freezing, a liquid releases heat and its kinetic energy increases.

  False
• What is specific heat capacity?

  Energy to raise temperature
• Latent heat is the energy absorbed or released during a phase change without a change in temperature
• Latent heat is related to changes in the potential energy of particles during phase transitions.
• How does heating water increase its internal energy?

  Increases kinetic energy
• When ice melts, it absorbs heat and its potential energy increases
• What happens to internal energy when cooking food?

  Increases kinetic and potential energy