Use a sharp pencil and a ruler. Give each diagram a title and label it with ruled label lines. Tap 🔍 See examples to see how the diagram usually looks – pictures online vary, so if one disagrees with the instructions, follow the instructions. ← All key diagrams
30. Particles in a solid, liquid and gas
Draw three boxes side by side. In the solid box, draw circles of the same size touching each other in neat rows. In the liquid box, draw circles still mostly touching but in a random arrangement. In the gas box, draw a few circles spread far apart, each with a short arrow showing it moving in a random direction. Under each box, write how the particles move: “vibrate about fixed positions”, “move around each other”, “move quickly in all directions”.
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31. Eureka can density practical
Draw a eureka (displacement) can from the side: a container with a spout near the top, filled with water up to the spout. Draw a stone hanging on a thread, lowered into the water. Draw a measuring cylinder under the spout collecting water. Label: “eureka can”, “irregular object”, “displaced water”, “measuring cylinder – volume of water = volume of object”. Write underneath: “measure mass with a balance; density = mass ÷ volume”.
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32. Heating curve for water
Draw axes with “time (s)” on the x-axis and “temperature (°C)” on the y-axis. Start below 0 °C and draw: a sloping line up to 0 °C; a flat line at 0 °C; a sloping line up to 100 °C; a flat line at 100 °C; then a final sloping line. Label the sections: “solid”, “melting”, “liquid”, “boiling”, “gas”. Label the flat parts “energy breaks bonds – temperature stays constant”.
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33. Cooling curve for wax
Draw axes with “time (min)” and “temperature (°C)”. Start at about 80 °C and draw a line curving downwards, then a flat section at about 55 °C, then a line curving downwards again towards room temperature. Label: “liquid cooling”, “freezing – temperature constant”, “solid cooling” and “freezing point” at the flat section.
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34. Gas pressure – particles hitting the walls
Draw a closed box containing about ten small circles spread out. Give each an arrow in a different direction. Show two or three particles bouncing off the walls with a small arrow on the wall at 90° to it. Label: “gas particles in constant random motion”, “collisions with the walls exert a force”, “pressure = force per unit area on the walls”.
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35. Sealed can before and after heating
Draw two identical sealed containers side by side. In the first, draw particles with short arrows and label it “cool”. In the second, draw the same number of particles with longer arrows and label it “heated”. Label the second one: “particles move faster → hit the walls more often and with more force → pressure increases (volume stays the same)”.
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36. Pressure vs volume graph (S only)
Draw axes with “volume (m³)” on the x-axis and “pressure (Pa)” on the y-axis. Draw a smooth curve that starts high on the left and falls steeply, then levels off (it should never touch either axis). Label: “fixed mass of gas at constant temperature”, “pV = constant”, “halving the volume doubles the pressure”.
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37. Bicycle pump (S only, HT)
Draw a cross-section of a cylinder with a piston and a handle at one end and an outlet at the other. Draw gas particles inside, closer together near the outlet. Draw an arrow on the handle labelled “force pushes piston in”. Label: “work is done on the gas”, “internal energy of the gas increases”, “temperature of the gas rises – the pump feels warm”.
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Check your drawings: Particle model topic page | Internal energy and changes of state | Gas pressure | Teach the topic: Particle model
