Welcome to the first post about the chemical elements! In these posts, I will talk about one element per post. Today, an element I'm sure you've all heard of: oxygen!
If you are confused by any of these terms, go to the glossary!
Facts about oxygen
Symbol: O
Electron configuration: [He] 2s22p4
Atomic number: 8
Key isotopes: 16O
Relative atomic mass: 15.999
Melting point: -218.79°C
Boiling point: -182.962°C
Electronegativity: 3.44
Oxygen is an element I'm sure you've all heard of. It is, after all, vital for life. Oxygen can be found normally in two forms: molecular oxygen, O2, the gas we breathe, and ozone, O3, which protects us from harmful UV rays coming from the Sun.
Oxygen gas wasn't in Earth's atmosphere at the beginning. It was pumped into the atmosphere as a byproduct of the photosynthesis of cyanobacteria, also known as blue-green algae. Nowadays, oxygen makes up 21% of Earth's atmosphere, and is recycled by the photosynthesis of plants.
The credit for discovering oxygen as an element was, oddly enough, given to three people - Joseph Priestley, Carl Wilhelm Scheele and Antoine Lavoisier. The first note of its discovery was published in 1774.
There are three naturally-occurring isotopes of oxygen:
Oxygen-16 is by far the most common. It is formed in stars by the addition of a helium nucleus to a carbon nucleus.
Oxygen-17 is the least common isotope of oxygen. It is thought to have originated from the beta decay of nitrogen-17 or by electron capture from fluorine-17.
Oxygen-18 is slightly more common than 17O, but not by much. However, it is important in medicine - it is used to create the radioactive isotope fluorine-18, which is used in fluorodeoxyglucose as a tracer in PET scans.
Oxygen is used in respiration by animals and is released back into the air as carbon dioxide. That is then used in photosynthesis by plants, being released back into the atmosphere as oxygen gas. Both processes keep the levels of oxygen stable in the atmosphere and ensure it doesn't uncontrollably rise or fall.
That's all for this week's blog post, so I'll see you next week! Bye for now!
Electron configuration: [He] 2s22p4
Atomic number: 8
Key isotopes: 16O
Relative atomic mass: 15.999
Melting point: -218.79°C
Boiling point: -182.962°C
Electronegativity: 3.44
Oxygen is an element I'm sure you've all heard of. It is, after all, vital for life. Oxygen can be found normally in two forms: molecular oxygen, O2, the gas we breathe, and ozone, O3, which protects us from harmful UV rays coming from the Sun.
Oxygen gas wasn't in Earth's atmosphere at the beginning. It was pumped into the atmosphere as a byproduct of the photosynthesis of cyanobacteria, also known as blue-green algae. Nowadays, oxygen makes up 21% of Earth's atmosphere, and is recycled by the photosynthesis of plants.
The credit for discovering oxygen as an element was, oddly enough, given to three people - Joseph Priestley, Carl Wilhelm Scheele and Antoine Lavoisier. The first note of its discovery was published in 1774.
There are three naturally-occurring isotopes of oxygen:
Oxygen-16 is by far the most common. It is formed in stars by the addition of a helium nucleus to a carbon nucleus.
Oxygen-17 is the least common isotope of oxygen. It is thought to have originated from the beta decay of nitrogen-17 or by electron capture from fluorine-17.
Oxygen-18 is slightly more common than 17O, but not by much. However, it is important in medicine - it is used to create the radioactive isotope fluorine-18, which is used in fluorodeoxyglucose as a tracer in PET scans.
Oxygen is used in respiration by animals and is released back into the air as carbon dioxide. That is then used in photosynthesis by plants, being released back into the atmosphere as oxygen gas. Both processes keep the levels of oxygen stable in the atmosphere and ensure it doesn't uncontrollably rise or fall.
That's all for this week's blog post, so I'll see you next week! Bye for now!