In GCSE Science students will look at the transfer of heat energy. This is the first of eight quizzes on that topic and it looks at the kinetic theory of matter and how the particles in solids, liquids and gases are affected by heat energy.
The kinetic theory of matter is one of the models that scientists use to help them to make sense of the world around them. The word kinetic always suggests something is moving and this theory is about the movement of particles in solids, liquids and gases. Particles transfer heat energy into kinetic energy. The kinetic theory can explain many properties of the three states of matter and is related to the amount of thermal energy distributed through the particles of an object. The particles in solids, liquids and gases have different amounts of energy, are arranged differently and move differently too.
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The kinetic theory explains why substances freeze and melt, why they boil and condense, and why evaporation causes cooling. It helps to explain why heat can be conducted by solids, how convection occurs in fluids and much more... including why solids cannot be compressed but gases can. In solids the particles are close together and fixed in place. Their only movement is to vibrate. Because of this, solids have definite shapes which they will keep - unless they are broken or cut. It is very difficult to push the particles in solids any closer together and so they can't be compressed.
In liquids the particles are only a little further apart than in solids, so liquids can't be compressed either. The main difference is that the particles in a liquid are free to move past each other, which is why liquids flow and take up the shape of the container in which they are placed. This movement was something that was first noted in 1827 by botanist Robert Brown. Brown observed that pollen grains floating on water moved around in random directions. It then took about 75 years until Albert Einstein came up with an explanation - water molecules were colliding with and pushing the pollen grains around.
Finally, in gases the particles are far apart and moving extremely rapidly in random directions. Because the particles are so widely spaced, gases are easily compressed.
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1.
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According to the kinetic theory, what are the particles in a heated solid doing? |
|
[ ] |
Vibrating more slowly than when the solid was cool |
[ ] |
Vibrating more rapidly than when the solid was cool |
[ ] |
Moving around more slowly than when the solid was cool |
[ ] |
Moving around more rapidly than when the solid was cool |
|
|
2.
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What will a substance do when it is heated? |
|
[ ] |
It will expand |
[ ] |
It will contract |
[ ] |
It will burn |
[ ] |
It will explode |
|
|
3.
|
Why does hot air rise? |
|
[ ] |
Heat naturally goes upwards |
[ ] |
It is pushed there by the cold air |
[ ] |
It is less dense than colder air |
[ ] |
It doesn't, this is a myth |
|
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4.
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Why are warm fluids less dense than their cold equivalent? |
|
[ ] |
Some of the fluid escapes from the particles so they are lighter |
[ ] |
Their particles are closer together |
[ ] |
Hot particles lose their quarks and become lighter |
[ ] |
Their particles are further apart |
|
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5.
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Which states of matter contract when you cool them? |
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[ ] |
Only gases |
[ ] |
Only solids |
[ ] |
Liquids and gases |
[ ] |
All of them |
|
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6.
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What happens to the particles of water vapour as it changes from a gas into a liquid to form a film of water on the inside surface of a cold window? |
|
[ ] |
When the particles of the water vapour hit the window, they stick to it |
[ ] |
The particles lose energy to the cold surface, slow down and become closer together |
[ ] |
The particles clump together because of the light coming through the window, forming water |
[ ] |
The particles speed up, forming water droplets |
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7.
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When a liquid is evaporating it cools down. Why? |
|
[ ] |
The faster particles escape leaving the slower particles behind |
[ ] |
There are fewer particles |
[ ] |
Evaporation needs a breeze and breezes cool things down |
[ ] |
It has a smaller volume than before |
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8.
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Which of the following would increase the speed at which a liquid evaporates? |
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[ ] |
Covering the liquid with a beaker |
[ ] |
Making sure that there were no draughts |
[ ] |
Spreading it out over a larger area |
[ ] |
All of the above |
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9.
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What happens to a gas in a sealed container when it is heated? |
|
[ ] |
The gas explodes |
[ ] |
The pressure of the gas increases |
[ ] |
The gas implodes |
[ ] |
The gas condenses |
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10.
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Some types of thermometer are filled with mercury, a liquid metal. Why do they work? |
|
[ ] |
Mercury is a metal so it conducts heat into the thermometer |
[ ] |
Mercury behaves in an unusual way |
[ ] |
Particles of liquids expand when they are heated and contract when they are cooled so the mercury fills more or less of the thermometer depending on the temperature |
[ ] |
The particles move faster or slower depending on the temperature so the mercury expands and contracts |
|
|
1.
|
According to the kinetic theory, what are the particles in a heated solid doing? |
|
[ ] |
Vibrating more slowly than when the solid was cool |
[x] |
Vibrating more rapidly than when the solid was cool |
[ ] |
Moving around more slowly than when the solid was cool |
[ ] |
Moving around more rapidly than when the solid was cool |
|
|
2.
|
What will a substance do when it is heated? |
|
[x] |
It will expand |
[ ] |
It will contract |
[ ] |
It will burn |
[ ] |
It will explode |
|
|
3.
|
Why does hot air rise? |
|
[ ] |
Heat naturally goes upwards |
[ ] |
It is pushed there by the cold air |
[x] |
It is less dense than colder air |
[ ] |
It doesn't, this is a myth |
|
|
4.
|
Why are warm fluids less dense than their cold equivalent? |
|
[ ] |
Some of the fluid escapes from the particles so they are lighter |
[ ] |
Their particles are closer together |
[ ] |
Hot particles lose their quarks and become lighter |
[x] |
Their particles are further apart |
|
|
5.
|
Which states of matter contract when you cool them? |
|
[ ] |
Only gases |
[ ] |
Only solids |
[ ] |
Liquids and gases |
[x] |
All of them |
|
|
6.
|
What happens to the particles of water vapour as it changes from a gas into a liquid to form a film of water on the inside surface of a cold window? |
|
[ ] |
When the particles of the water vapour hit the window, they stick to it |
[x] |
The particles lose energy to the cold surface, slow down and become closer together |
[ ] |
The particles clump together because of the light coming through the window, forming water |
[ ] |
The particles speed up, forming water droplets |
|
|
7.
|
When a liquid is evaporating it cools down. Why? |
|
[x] |
The faster particles escape leaving the slower particles behind |
[ ] |
There are fewer particles |
[ ] |
Evaporation needs a breeze and breezes cool things down |
[ ] |
It has a smaller volume than before |
|
|
8.
|
Which of the following would increase the speed at which a liquid evaporates? |
|
[ ] |
Covering the liquid with a beaker |
[ ] |
Making sure that there were no draughts |
[x] |
Spreading it out over a larger area |
[ ] |
All of the above |
|
|
9.
|
What happens to a gas in a sealed container when it is heated? |
|
[ ] |
The gas explodes |
[x] |
The pressure of the gas increases |
[ ] |
The gas implodes |
[ ] |
The gas condenses |
|
|
10.
|
Some types of thermometer are filled with mercury, a liquid metal. Why do they work? |
|
[ ] |
Mercury is a metal so it conducts heat into the thermometer |
[ ] |
Mercury behaves in an unusual way |
[ ] |
Particles of liquids expand when they are heated and contract when they are cooled so the mercury fills more or less of the thermometer depending on the temperature |
[x] |
The particles move faster or slower depending on the temperature so the mercury expands and contracts |
|
|