Thousands of people are dying daily, especially in India, from lack of oxygen. Which is odd since oxygen is the most common element on Earth. The atmosphere is 20% oxygen, the oceans are nearly 90% oxygen by weight, and it makes up nearly half of the Earth’s crust. More than half of your weight is oxygen atoms, no matter your size. But people in hospitals with serious respiratory issues, as with COVID, are helped by nearly pure concentrated oxygen gas to enrich the blood.
Perhaps in your school science laboratory you separated water into hydrogen and oxygen with an electric current, but that takes a lot of energy. It is also possible to separate oxygen and nitrogen from liquid air as they have different boiling points. But most oxygen concentrators pass air over a material called a molecular sieve, typically zeolite (aluminosilicate) that absorbs nitrogen while leaving oxygen alone. Then the zeolite is made to expel the nitrogen back into the air by a “pressure swing.” All hospitals should have these; they are inexpensive, safe and just need power and air.
Life needs oxygen as well as carbon. Both elements were made in stars; after the Big Bang only hydrogen, helium and a little lithium existed. In 1946 English astrophysicist Fred Hoyle explained that when stars collapse under their own gravity the central density can reach 10 million tons per cubic meter (per cubic yard if you prefer) with a temperature of 40 billion degrees (Fahrenheit or Celsius, it doesn’t much matter). Only then could the positively-charged hydrogen and helium nuclei overcome their electrical repulsion, stick together and make heavier elements like carbon, nitrogen and oxygen. Oxygen is made when a helium nucleus sticks to carbon. When light elements fuse together to make heavier ones, energy is released – that is called nuclear fusion, as in a hydrogen bomb. Some stars explode, scattering those elements into space as gas. Some stays in space, some condenses making new stars, and some ends up in planets and eventually in you.
Yes, we are all made of stardust – together with hydrogen from the Big Bang 13.8 billion years ago. Elements heavier than iron, like gold or uranium, need even more extreme conditions, in supernova explosions or colliding neutron stars.
Breathe deep and appreciate all that oxygen enriching your blood, and I hope you get enough. It was once deep inside a star.
