In Chapter 1 of Astrobiology, A Very Short Introduction, the author talks about some properties of one element in particular tha
t is vital to life on Earth. In particular, he mentions this element's ability to form long chains, single, double, and triple bonds, as well as rings. Which elements has these properties?
Carbon has four electrons in its valence shell, so it generally shares it in a covalent bond. This element needs four electrons to be stable, so it can form single (such as the bond with hydrogen), double (such as the bond with oxygen) or triple bonds (such as the bond with nitrogen).
It can also form bonds with other carbon, and they can form longs chains, that's why there are a lot of organic compounds (the compounds with carbon). Carbon can form rings too, such as in benzene.
