What is the temperature range in the exosphere?

The temperature range in the exosphere is often characterized as hot, with temperatures that can potentially exceed 2000 °C. This is due to the presence of low-density particles that absorb high-energy solar radiation. In this outermost layer of the atmosphere, the molecules are so sparse that they can gain significant kinetic energy from solar radiation, leading to extremely high temperatures.

While temperatures in the exosphere can be described as hot, it is essential to note that this does not imply a comforting heat like we experience at lower altitudes. Instead, the high temperatures are a result of the particles moving at extremely high speeds, even though there are very few of them.

In contrast, options that describe the temperature as cold, consistently around 0 °C, or gradually decreasing with altitude do not accurately reflect the conditions present in the exosphere. Temperatures in the lower layers of the atmosphere do gradually decrease with altitude, but in the exosphere, high-energy solar radiation contributes to higher temperature readings. Thus, the characterization of the exosphere's temperature as hot is correct, making it the appropriate choice.