Which of the following can be an indicator of a higher average kinetic energy in a substance?

The correct answer is higher temperature, as it directly correlates to an increase in the average kinetic energy of the particles in a substance. In thermodynamics, temperature is a measure of the average kinetic energy of the molecules in a material. As temperature increases, the vibrational, rotational, and translational motion of the molecules becomes more vigorous, leading to a greater average kinetic energy.

Higher temperatures generally mean that the particles are moving more rapidly, which increases their energy. This principle is foundational in understanding thermodynamic processes and helps to explain how various substances behave at different temperatures.

Other options, like lower temperature, decreased molecular weight, and solid state, would typically suggest lower kinetic energy. Lower temperatures result in reduced molecular motion, while an increase in molecular weight can lead to slower movement due to the heavier mass of the particles. The solid state of matter indicates that the particles are closely packed and only vibrate in place, contributing to lower average kinetic energy compared to liquids or gases at higher temperatures.