Energy Changes in Melting and Boiling Flashcards

1️⃣ Familiarise yourself with the flashcards:

  • Look through all the flashcards to see what's on both sides.
  • Make sure you understand the information on each card. If something's unclear, click the link to the revision notes at the bottom of the page for more details.

2️⃣ Test yourself:

  • Look at the question or prompt on each card and try to remember the answer before flipping it over.
  • Check the answer and make a note of any cards you find challenging and need to go over more.

3️⃣ Consistently Review and Practice:

  • Use spaced repetition: spend more time on the cards you struggle with and go over them more often.
  • Regularly review all the flashcards to help you better understand and retain the information over time.

Note: We may include questions that have multiple correct answers. It's useful to remember specific examples to understand these concepts better.

PERSONALISED 1-TO-1 TUTORING

Need more help on this topic? Get 1-to-1 support

Get support with clear explanations, practice and feedback (Ages 5 to 16).

  • DBS-checked tutors
  • Flexible times
  • Parents can be updated

Want an ad-free experience? Subscribe to remove ads

During melting and boiling, does a substance take in energy or give out energy?

It takes in energy from the surroundings.

Why does a solid need energy to melt?

The energy makes the particles vibrate more so they can break some of the forces holding them in fixed positions.

Why does a liquid need energy to boil?

The energy makes the particles move faster so they can break almost all the forces and escape as a gas.

During melting or boiling, why does the temperature stay the same even when you keep heating?

Because the added energy is used to change the state by breaking forces between particles, not to increase the temperature.

On a heating curve, what do the flat (horizontal) sections at the melting and boiling points show?

They show times when energy is being used to change state, so the temperature does not rise.

Why does boiling usually need more energy than melting for the same substance?

To boil, particles must break almost all the forces and move far apart, so more energy is needed than to melt.

What happens to energy when a liquid freezes or a gas condenses back to a liquid?

Energy is released to the surroundings as forces form between the particles.

If forces between particles are very strong, how much energy is needed to melt or boil the substance?

More energy is needed to overcome the strong forces, so it has higher melting and boiling points.

What name is given to a change, such as melting or boiling, that takes in energy from the surroundings?

It is called an endothermic change.