Temperature And The Kelvin Scale (T5)

Question 1

What is the SI (international system) unit for absolute temperature?

Answer 1

Kelvins

K

Question 2

What is ‘absolute zero’ and what effect will it have on gas molecules, considering the fact that heating them up increases their average speed?

Answer 2

If the temperature is gradually reduced there will come a point when the molecules actually all stop moving. At this temperature the molecules have zero total kinetic energy so it is not possible to extract any more heat energy from them. They have reached the coldest temperature that is it possible to reach - Absolute Zero. Nothing can go down to a lower temperature than this, no matter what.

Question 3

What temperature is Absolute Zero?

Answer 3

-273 degrees centigrade (to the nearest whole number)

Question 4

How do you convert the kelvin temperature to degrees Celsius?

Answer 4

The kelvin temperature starts at absolute zero which is -273 degrees C.

So to convert from Celsius to kelvins simply add 273 and to convert from kelvins to Celsius simply subtract 273.

Question 5

The Kelvin scale helps us to make more sense of physics theories because the average kinetic energy of the molecules in a gas is proportional to the temperature in kelvins. Why can this statement not be true if you use the Celsius or any other scale?

Answer 5

Because they all involve some negative values