Promethium
Promethium is a synthetic radioactive chemical element that has the symbol Pm on the periodic table. It has the atomic number 61 which means it has 61 protons in its atom. It is the only synthetic element in the Lanthanide group as all its isotopes are radioactive. Together with Technetium, these are the only two radioactive elements below lead. Most Promethium is artificially produced. The longest-living isotope of promethium is 145 Pm, with a half-life of 17.7 years.
Uses
Promethium is used in the illuminated digits of some clocks, its Beta Radiation may be used to measure thickness.
Written for younger readers
Promethium, in simpler words
This version comes from Wikijunior, a set of books written for children aged 8 to 11. It is shorter and uses plainer language than the article above.
From Wikijunior: The Elements
NOTOC
It is likely silvery coloured and somewhat hard. Not many people have seen it as it is very rare and radioactive.
Scientists had guessed that there an element with atomic number 61 existed many years before it was found. After a number of claims to have found it by different scientists, it was decided that promethium did not occur naturally. In 1945 the Oak Ridge National Laboratory in the United States found Promethium during an investigation of the results of splitting uranium fuel in a nuclear reactor. They were too busy at the time (this was during World War II) to tell anyone about the discovery so it only became widely known in 1947.
The first suggested name was “clintonium”, named after the laboratory where it was found, but in the end “prometheum” was suggested after the name of Prometheus, the Titan in Greek mythology who stole fire from Mount Olympus. The spelling was changed to “promethium” to match the style of names of other similar elements.
Promethium is found in the Earth’s crust. It is found in uranium ore because of uranium’s decay, but not much promethium exists in the world.
Promethium is used to make small atomic batteries. Like radium, it is also sometimes used to paint the hands and the numbers on the dial of a watch to make them glow in the dark.
It is dangerous as it is very radioactive. This radioactivity can cause cancer later in life.
Where this page comes from
The article above is adapted from “Promethium” on Simple English Wikipedia, by its contributors. We removed reference markers, navigation boxes and tables, expanded measurement templates into readable numbers, and kept the prose otherwise intact. The simpler version is adapted from Wikijunior on Wikibooks.
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