Question

A gas in a laboratory vessel is cooled. All the molecules of the enclosed gas cease to have any motion.

What is the temperature in the vessel?

Responses

273 K
273 K

−273 K
negative 273 uppercase K

273°C

273°C

−273°C

Answer 1

All molecular motion would stop at absolute zero, which is 0 K = −273.15°C.

So the correct choice from your list is −273°C (approximately). Note: negative temperatures in kelvins are not physically meaningful here, and in practice absolute zero cannot be reached exactly (third law of thermodynamics).