Page 128 - Knowledge Organiser Yr7 24-25

Knowledge Base: Science 7.4 Energy Year 7
4. Food as a Store of Energy
4.6
Draw a labelled diagram showing how you could compare the energy content in different crisps:
4. Food as a Store of Energy
4.1 What store of energy is in food?
Chemical.
4.2
When we eat food energy is transferred to what stores?
Thermal and kinetic stores.
4.3
How many joules are in one kilojoule (1kJ)?
1000J.
4.4
Which types of food have the greatest store of energy?
Fatty foods.
4.5
When food is burnt there is a transfer of energy between which stores?
Chemical to thermal.
5. Temperature
5.1 What is the unit for temperature?
5.2 How can temperature be measured?
Degrees Celsius oC. With a thermometer.
6. Conduction
6.1
What type of energy transfer is conduction?
Heating transfer.
6.2
In which state of matter does conduction occur?
Solid.
6.3
Why can conduction not occur in liquids and gases?
The particles are not arranged close enough together.
6.4
During conduction, how is energy transferred?
• Energy is transferred to the kinetic store of the particles.
• The particles vibrate more.
• The vibrations cause nearby particles to vibrate.
• Energy is transferred through the vibrations.
6.5
Name a material that is a good thermal conductor.
Metal.
6.6
Name a material that is a poor thermal conductor.
Plastic or glass.
6.7
What do you call a material which is a poor thermal conductor?
An insulator.
5.3
What is meant by temperature of a substance?
The average energy of the particles in the substance.
5.4
What effect will increasing temperature have on the movement of particles in a solid?
Particles will gain energy and vibrate more.
5.5
What effect will increasing temperature have on the movement of particles in a liquid or a gas?
Particles will gain energy and move more.
5.6
Why does a cup of tea left on the side go cold?
Energy is transferred from the hot cup of tea to the cool surroundings until they reach the same temperature.
5.7
What is meant by thermal equilibrium?
When there is no transfer of energy by heating between objects because they are at the same temperature.
128