The average kinetic energy of water molecules is directly related to the temperature of the water. In this case, the temperatures are:
- L: 40 ºC
- M: 88 ºC
- N: 21 ºC
To order the samples from greatest to least average kinetic energy, we can arrange the samples based on their temperatures:
- M (88 ºC) - greatest average kinetic energy
- L (40 ºC) - middle average kinetic energy
- N (21 ºC) - least average kinetic energy
Thus, the correct order from greatest to least average kinetic energy is:
M, L, N
So the response is M, L, N.