Particle model and matter Flashcards
1
Q
What is a conductor?
A
- a conductor is a material that transfers thermal energy quickly through it
e.g copper, aluminum and steel
2
Q
What is thermal conductivity?
A
- the greater the thermal conductivity of a material, the more energy per second it transfers by conduction
3
Q
You are buying a saucepan and have to choose between a glass saucepan and a copper one. Which would you choose and why?
3 marks
A
- copper
- has a higher thermal conductivity
- so it would conduct heat into the saucepan contents more quickly
4
Q
Explain why different parts of the saucepan use different materials?
A
- the handle is plastic which is a poor conductor
- this stops the person holding it getting burnt
- the pan is metal which is a good conductor
- this allows heat to get into the pan
5
Q
Factors that affect how good an insulator is
A
- more layers of insulation
- lower thermal conductivity
- thicker material
6
Q
What is an insulator?
A
- an insulator is a material that transfers thermal energy slowly through it
7
Q
How can we reduce heat loss?
A
- bricks with lower thermal conductivity
- foil between radiators and the wall
- double glazed windows
- cavity wall insulation
- loft insulation
- use heating less
8
Q
How do you find the specific heat capacity of a piece of metal
A
- set up apparatus (thermometer, immersion heater, metal block)
- check the temperature of the metal
- turn on the heater
- check the voltmeter and ammeter readings
- every minute record the temperature
- use energy = voltage x current x time
9
Q
Specific Heat capacity
A
- specific heat capacity of a substance is the energy needed to the raise the temperature of 1kg of the substance by 1 degrees.
10
Q
When does a substance take more energy to heat up
A
- it is heavier
- it needs to increase temp more
- it has higher SHC
11
Q
Equation
A
energy transferred= mass x specific heat capacity x temp change
12
Q
Infrared radiation
A
all objects emit and absorb ir
perfect black body- object that absorbs all the radiation that hits it
