Nitrogen
All we are is a lot of talking nitrogen. ~ American playwright Arthur Miller (We are also a lot of farting nitrogen. Nitrogen is the main constituent of flatus (20–90%), followed by carbon dioxide (10–30%).)
Scottish physician Daniel Rutherford is credited with discovering nitrogen in 1772, though he did not identify it. He simply killed a mouse to show that it couldn’t breathe once the ambient oxygen had been used up.
Rutherford’s discovery was the leftover gas besides oxygen: mostly nitrogen, with residual carbon dioxide; what he called noxious air (fixed air). Rutherford’s noxious air provided him further proof of his conviction to phlogiston theory.
Imaginative German alchemist Johann Joachim Becher concocted the phlogiston theory in 1667. By his account, phlogiston was an odorless, tasteless, colorless, massless fire element, contained within combustible substances, and released during combustion.
Once burned, a dephlogisticated substance was held to be in its ‘true’ form, the calx. Phlogiston theory purported to explain both combustion and the rusting of metals, processes now collectively known as oxidation.
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If carbon is the king of organic chemistry, nitrogen is queen. Nitrogen (N) is an essential element in building amino acids and nucleic acids, which are respectively the building blocks of proteins and genomes. Nitrogen is the 4th most abundant element in organisms, and the 7th most common in the cosmos.
While essential and abundant, nitrogen only reluctantly plays its organic role. Nitrogen has 5 electrons in its outer shell, and so is trivalent in most compounds. The triple bond of molecular nitrogen is a tough bond to break.