What are air particles doing in an undisturbed state?

Air particles are a mixture of solids and liquids that are microscopically tiny and suspended by air currents. It can stay in the atmosphere for a few hours to a month or two. Their constituents can be various harmful substances such as heavy metals - lead, nickel, arsenic, cadmium or polycyclic aromatic hydrocarbons

Explanation:

Air particles, nitrogen dioxide and ground-level ozone are now considered to be the three most polluting substances in human health. Exposure during peak concentration and long-term exposure to these pollutants can cause damage from respiratory distress to premature death.

answer; ///i believe the answer your looking for is (ribosomes);

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.