Oxygen+by+gymnastics179

Element projects: Oxygen Most people know the importance of oxygen. That it is a main component of the air plants and animals breathe that helps them survive. What most people do not know is the theories that led to the discovery of oxygen. They do not know about the subatomic particles, the atoms that make oxygen. They only know of oxygen as a gas, not a liquid or a solid. And most people know a few of the uses of oxygen.

Oxygen was “discovered” in the 18th century. The first person to “discover” it was Carl Scheel. Scheel heated nitric acid, and discovered at a certain temperature, it boiled and became a gas. He found that the gas burned easily so he named it ‘fire air’. Later in the century, Joseph Priestly discovered that plants gave off a gas that mammals needed to survive. He did not know that it was a main component of air or that it was oxygen. Then come the “Phlogiston Theory”. Scientists believed that when anything burned a special flammable substance called “phlogiston” was involved. The scientist who truly discovered oxygen was Antoine Lavoiser. Lavoiser discovered that Scheel’s fire air was the same as Priestly’s gas. He was able to prove that to the other scientists, as well as the fact that phlogiston did not exist. He named it oxygen, after “oxys", the Greek word for acid, and “genos”, the word for forming. Lavoiser also discovered the conservation law. Mass is never lost in a chemical reaction, but it can change.

Without Lavoiser’s discovery of oxygen, it would have been much, much harder to find the atomic mass and atomic number for oxygen. Without that, our periodic table of elements would be very different as well. Scientists discovered that oxygen has eight protons and electrons. Protons have a positive charge and electrons have a negative charge, so they cancel each other out, and with neutrons, of which oxygen also has 8, we get electricity. Since there are 8 protons, the atomic number for oxygen is 8. The atomic mass is 16. A Bohr model of an oxygen atom would have 8 protons in the nucleus and 8 neutrons. There would be 2 electrons on the first shell, and 6 on the second shell. Since there are only 6 electrons on a shell that holds 8, oxygen can be very reactive, and needs to bond with elements that have two electrons to spare.

Oxygen is a very useful element. Bottled oxygen can be used to breathe underwater, on high mountains, and in airplanes and submarines. They also put it in steel to make it stronger. Liquid oxygen is also very useful. It supplied the power that first brought astronauts to the moon. Many of the great discoveries would not be possible without oxygen, but I think the two most useful things that oxygen does are making fire and supplying air for us to breathe. [|Oxygen] takes up over 20% of the atmosphere, where would we be without this critical element? It’s thanks to oxygen that we are alive today.

Most people think that oxygen is just a gas, only the air we breathe. Those people would be mistaken. The most common form of oxygen is a gas, but it melts at only -297.4° Fahrenheit. At this point it is a pale blue liquid. At -361° Fahrenheit, oxygen becomes a pale blue solid. When oxygen is filtered out of air it becomes a chemical called “LOX”. LOX is used to increase the strength of most man-made metals. POSTER OF OXYGEN