the force, or mass, per unit area of a column of air.
the atmospheric layer closest to the earth's surface.
the second layer above earth's surface.
concentrated in a portion of the stratosphere that keeps out 95% of the sun's harmful U.V. radiation.
chemicals or substances emitted into the air from natural processes and human activities at concentrations high enough to cause harm.
pollutants that react with one another and with other natural components of air to form new harmful chemicals.
a group of major air pollutants from burning of fossil fuels. One prevents normal binding of oxygen to hemoglobin and causes negative health effects and the other in this group is a greenhouse gas.
a group of major air pollutants from burning fossil fuels, lightning, and certain bacteria. A secondary airpollutant is formed with the oxygen in the air and is a reddish-brown gas.
HNO3 formed when NO2 reacts with water vapor in the atmosphere. It is a harmful component of acid deposition and plays a role in photochemical smog.