| − | The [[atmosphere]] surrounding the [[Earth]] consists of a mixture of gases commonly called '''air'''. The most common gases are [[nitrogen]] (77%) and [[oxygen]] (about 22%). There are other gases as well, but in very small quantities. The air is important for almost all life on Earth including [[plant]]s and [[animal]]s. Plants need carbon dioxide for [[photosynthesis]]. Animals need to breath air to get the oxygen they need to survive. As you move up in [[altitude]] through the atmosphere, the concentration of air molecules decreases. The air is thinner higher in the atmosphere because there is lower pressure the higher you go up. There is a special layer of air molecules high in the [[stratosphere]] layer of Earth’s atmosphere, called the [[ozone layer]]. The composition of the atmosphere is different in the ozone layer. There are more [[ozone]] molecules than anywhere else. Ozone molecules help block some of the [[Sun]]’s strongest rays. Currently, [[scientist]]s are monitoring this layer. It has recently become so thin at the [[South Pole]] where the molecules are being destroyed that we call it a hole. | + | The [[atmosphere]] surrounding the [[Earth]] consists of a mixture of gases commonly called '''air'''. The most common gases are [[nitrogen]] (77%) and [[oxygen]] (about 22%). There are other gases as well, but in very small quantities. The air is important for almost all life on Earth including [[plant]]s and [[animal]]s. Plants need carbon dioxide for [[photosynthesis]]. Animals need to breath air to get the oxygen they need to survive. As you move up in [[altitude]] through the atmosphere, the concentration of air molecules decreases. The air is thinner higher in the atmosphere because there is lower pressure the higher you go up. |
| | + | There is a special layer of air molecules high in the [[stratosphere]] layer of Earth’s atmosphere, called the [[ozone layer]]. The composition of the atmosphere is different in the ozone layer. There are more [[ozone]] molecules than anywhere else. Ozone molecules help block some of the [[Sun]]’s strongest rays. Currently, [[scientist]]s are monitoring this layer. It has recently become so thin at the [[South Pole]] where the molecules are being destroyed that we call it a hole. |