Copy each passage into your book and fill in the numbered gaps using the word bank. Then check your answers. ← All topics
1. States of matter and density (C+S)
In a solid, the particles are packed closely in a (1)______ pattern and vibrate about fixed positions. In a liquid, the particles are close together but can (2)______ past each other. In a gas, the particles are far apart and move quickly in (3)______ directions. Density is mass per unit (4)______ (ρ = m ÷ V). Gases have a much (5)______ density than solids because their particles are much further apart.
Word bank: lower · move · random · regular · volume
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1 regular · 2 move · 3 random · 4 volume · 5 lower
2. Measuring density – required practical (C+S)
To find the density of a regular solid, measure its mass with a (1)______ and calculate its volume from its length, width and height. For an irregular object, lower it into a (2)______ can full of water and collect the displaced water in a measuring (3)______; the volume of water equals the volume of the object. For a liquid, measure the mass of an empty measuring cylinder, then the mass with the liquid in it – the difference is the mass of the (4)______.
Word bank: balance · cylinder · eureka · liquid
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1 balance · 2 eureka (displacement) · 3 cylinder · 4 liquid
3. Internal energy and changes of state (C+S)
Internal energy is the total (1)______ energy and potential energy of all the particles in a system. Heating a system increases its internal energy, which either raises its (2)______ or changes its state. Changes of state are (3)______ changes: they can be reversed, and (4)______ is conserved. While a substance is changing state, its temperature stays (5)______, because the energy is being used to break the (6)______ between particles.
Word bank: bonds · constant · kinetic · mass · physical · temperature
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1 kinetic · 2 temperature · 3 physical · 4 mass · 5 constant · 6 bonds
4. Specific latent heat (C+S)
Specific latent heat is the energy needed to change the (1)______ of 1 kg of a substance with no change in temperature: E = mL. The specific latent heat of (2)______ is for changing from solid to liquid. The specific latent heat of (3)______ is for changing from liquid to vapour. On a heating graph, the (4)______ sections show where the substance is changing state. In calculations, m is the mass that has (5)______ state – not the starting mass.
Word bank: changed · flat · fusion · state · vaporisation
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1 state · 2 fusion · 3 vaporisation · 4 flat · 5 changed
5. Gas pressure and temperature (C+S)
The particles in a gas are in constant (1)______ motion. The temperature of a gas is related to the average (2)______ energy of its particles. When the particles hit the walls of their container, they exert a (3)______; the force per unit area is the gas pressure. If a gas is heated at constant volume, the particles move faster, so they hit the walls more (4)______ and with more force, so the pressure (5)______.
Word bank: force · frequently · increases · kinetic · random
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1 random · 2 kinetic · 3 force · 4 frequently · 5 increases
6. Pressure and volume; doing work on a gas (S only)
For a fixed mass of gas at a constant (1)______, pV = constant. If the volume is halved, the pressure (2)______, because the particles hit the walls more often. (HT) Work is done on a gas when it is (3)______, for example in a bicycle pump. This transfers energy to the gas, increasing its internal energy, so its temperature (4)______.
Word bank: compressed · doubles · increases · temperature
Check your answers
1 temperature · 2 doubles · 3 compressed · 4 increases
