What is the rarest element?
Here is a link. Read about the discovery of elements 110 to ...... One of those I believe produced one atoms of the element.
http://www.google.com/#q=rarest+element
Read about flerovium. Only one atom was prepared. Element #114.
http://www.webelements.com/flerovium/
The rarest element, by natural occurrence, is astatine (symbol: At). Astatine is a highly radioactive element with atomic number 85. It was discovered in 1940 and is the least abundant element in the Earth's crust. Astatine is produced by the decay of uranium and thorium, but only very small amounts are found in nature as it has a short half-life. The rarity of astatine makes it challenging to study and obtain for experimental purposes.
To determine the rarity of an element, you can consult the periodic table or scientific databases. These resources provide information about the natural abundance of elements, their occurrence in minerals or ores, and synthetic production methods if applicable.