| A | B |
|---|
| weather | Condition of earth's atmospere an a particular place and time. |
| atmosphere | The layer of gases that surrounds the earth. |
| ozone | A form of oxygen that contains three oxygen atoms in each molocule instead of the usual two. |
| water vapor | Water in the form of a gas. |
| Nitrogen | Makes up about three fourths of the air. |
| oxygen | The second-most-abundant gas in the air |
| carbon dioxide | Makes up 0.036 percent of the air. |
| argon | Makes up 0.93 percent of the air. |
| pollutants | Harmful substances in the air, water, or soil. |
| smog | Is formed when coal smoke combines with water dropletts in humid air. |
| acid rain | Forms when nitrogen oxides and sulfur oxides combine with water in the air to form nitric acid and sulfuric acid. |
| photochemical somg | Is formed when noitrogen oxides, hydrocarbons, and other air pollutants react with each other in the presense on sunlight to form a mix of ozone and other chemicals. |
