The apartment’s explosion, reportedly caused by a gas leak, produced a violent release of gas and heat. The heat increased the ____________ of the air in the room, which means an increase in the air's molecular energy of motion.

The answer is "Temperature"

temperature

The missing word in the sentence is "temperature." The heat from the explosion caused an increase in the temperature of the air in the room. Temperature is a measure of the average kinetic energy, or molecular energy of motion, of the particles in a substance, such as air.

To find the missing word, you can analyze the context of the sentence. The sentence mentions an explosion caused by a gas leak, which resulted in a release of gas and heat. This suggests that the explosion generated high temperatures, leading to an increase in the molecular energy of motion of the air in the room. By understanding the relationship between heat and temperature, you can deduce that the missing word is "temperature."