Thermal properties Flashcards
What is thermal expansion?
When a material is heated, the particles have more kinetic energy so move more, resulting in more space between the molecules - and ultimately resulting in the material expanding
Which state of matter experiences the most thermal expansion
Gases, because the particles have the most freedom to move
Describe how temperature is measured by a liquid-in-glass thermometer
- as temperature rises/falls, the liquid expands/contracts
- a scale is used to calibrate and convert expansion to a temperature value
Give examples of fixed points used to calibrate thermometers
- melting point (0°C)
- boiling point (100°C)
What is the sensitivity of a thermometer
The change in length per degree change in temperature
Describe how to increase the sensitivity of a thermometer
- bigger bulb
- narrower bulb
Define range
The difference between the maximum and minimum values
How can the range of a thermometer be increased
- wider bore
- longer stem
Define linearity
When a change in input causes the same change in output
Define specific thermal capacity
The amount of energy needed to raise the temperature of 1kgof a substance by 1°C
Define internal energy
The energy stored by particles within a system
What kind of energy are stored as internal energy
Kinetic and Potential
How does heating affect internal energy
It increases internal energy. The particles gain energy and move more, increasing their kinetic energy and therefore increasing the overall internal energy
What does an increase in internal energy result in
A change of state or an increase in temperature
Define specific latent heat
The amount of energy needed to change the state of 1kg of a substance
