Melting: particle model
I can use the particle model to explain why substances have different melting points, and use a thermometer to measure melting points.
- Year 7
Melting: particle model
I can use the particle model to explain why substances have different melting points, and use a thermometer to measure melting points.
Lesson details
Key learning points
- In the solid state, forces of attraction between particles hold them in fixed positions.
- In the liquid state, particles are held together but have enough energy to break free to move around.
- The stronger the force of attraction between particles in a substance, the higher its melting point.
- Water freezes at 0ºC, room temperature is about 20ºC and body temperature is about 37ºC.
- The bulb of a thermometer is made of very thin glass and is delicate.
Keywords
Melting - Melting is when a substance changes from a solid state to a liquid state.
Melting point - The melting point of a substance is the temperature at which it changes from solid state to a liquid state.
Forces of attraction - Forces of attraction hold particles together.
Regular arrangement - In a solid state the particles are in a regular arrangement.
Random arrangement - In a liquid state the particles are in a random arrangement.
Common misconception
Particle spacing can be overemphasised at the expense of particle movement.
Ensure pupils understand that although particles can move over each other, the forces of attraction mean that the particles are touching.
Equipment
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the state of matter where particles are closely packed in a fixed arrangement?
Q2.Which of the following is a common temperature measurement tool?
Q3.Arrange the following states of matter, based on the freedom of particle movement (from least to most):
Q4.Match the states of matter with their particle arrangements:
