Up to now, humans have recorded a total of 118 elements in the periodic table.
The reason is quite simple: Among the dozens of elements found in the Earth’s crust, five elements including oxygen, silicon, aluminum, iron and calcium account for a total of more than 92%.
In the opposite direction, people also recorded the existence of astatine – a natural element considered to be the rarest on Earth at the present time.
Astatine is named after the Greek word meaning `unstable`.
As an unstable isotope, astatine has a half-life of one second or less.
Although scientists can process the element directly, they can only do so artificially, through nuclear reactions – usually by bombarding bismuth-209 with alpha particles.
Therefore, most of what we know about this element comes from theory rather than practical testing.
However, this conjecture also leads to more debate about astatine, such as whether it is a metal or a halogen.
Although so rare as to be almost non-existent – and so puzzling that we know essentially nothing about it with any certainty – astatine turns out to have some pretty important practical applications.
`Astatine is the Goldilocks of α emitters,` Mehran Makvandi, a radiologist at the University of Pennsylvania School of Medicine (USA), commented on astatine.
Goldilocks here is a concept named after a little girl in the children’s story `The Three Bears`.
Simply put, astatine here possesses a sufficient ‘strength’.
Astatine has an extremely short half-life, meaning it will not last for a long time.
If scientists can attach astatine isotopes to molecules that target cancer cells, they could create an anti-cancer treatment that can cut through the DNA of cancer cells.
Of course, this method still has many barriers to development.
That may be why the element is still officially listed as having no biological role or use beyond research.
From another perspective, the fact that people do not understand astatine well can be considered a good thing.
Refer to IFL Science
