et oxygen. Oxygen makes up only 20% of the air around us, but it is the reason we need to breathe. When we inhale, oxygen gets into our lungs, then it diffuses into the blood and reacts with red blood cells to produce energy. Energy is vital in every thing we do. The second reason oxygen is so important is that oxygen combines with hydrogen to make water. Without water there would be no Earth. We ourselves are made mostly of water! When we lose some of this water, we need to drink to replenish it. Also, fish need the free oxygen that is dissolved in water and fish are a large part of the food web. Lastly, oxygen reacts with almost all of the other elements to form many compounds that are very important to us. For example, oxides. A lot of oxides are used to produce bleaches and disinfectants.It’s amazing how many organic and non-organic things can be formed and function out of just 109 elements. I believe that out of these elements, the most important ones are nitrogen, carbon and oxygen. As part of food chain, nitrogen supports all living organisms, including humans. My second choice, carbon, is also an important part of the food chain. A thing is classified organic only if it contains carbon. Carbon also provides our fuels and is used in the process of photosynthesis. Finally, oxygen. Oxygen is part of the oxidation process, which gives energy to all living organisms. Also, oxygen is part of water, which is most abundant and one of the most important compounds on Earth. All of these three elements together with hydrogen make lipids, proteins, carbohydrates, amino acids, DNA and RNA. These are the basic building blocks of life. ...
