Answer:
A) The helium at 15 degrees Celsius has a higher average kinetic energy that the sample at 215 K.
Step-by-step explanation:
First, we must compare the two different temperatures in the same units. To convert Celsius into kelvin we must add it 273, so
K = °C + 273 = 15°C + 273 = 288K
And 288K > 215 K then 15°C > 215K
The increase of temperature in a gas sample causes an increase in the atom’s movement, i.e. the atoms move faster when they are heated and, for this reason, the kinetic energy of the system increases.
As helium at 15°C (288K) implies that has a higher temperature than helium at 215K, then its kinetic energy will be higher too.