promethium

American  

[pruh-mee-thee-uhm] / prəˈmi θi əm /

noun

Chemistry.

1. a rare-earth, metallic, trivalent element. Pm; 61.

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promethium British  

/ prəˈmiːθɪəm /

noun

1. a radioactive element of the lanthanide series artificially produced by the fission of uranium. Symbol: Pm; atomic no: 61; half-life of most stable isotope, ¹⁴⁵ Pm: 17.7 years; valency: 3; melting pt: 1042°C; boiling pt: 2460°C (approx.)

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promethium Scientific  

/ prə-mē′thē-əm /

1. A radioactive metallic element of the lanthanide series. Promethium does not occur in nature but is prepared through the fission of uranium. It has 17 isotopes, one of which is used to make long-lived miniature batteries that work at extreme temperatures for up to five years. The longest-lived isotope, Pm 147, has a half-life of 2.5 years and is used as a source of beta rays. Atomic number 61; melting point 1,168°C; boiling point 2,460°C; valence 3.

2. See Periodic Table

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Etymology

Origin of promethium

From New Latin, dating back to 1945–50; Prometheus, -ium

Example Sentences

The ORNL-led team of scientists prepared a chemical complex of promethium, which enabled its characterization in solution for the first time.

From Science Daily

The 17 elements are: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium.

From Reuters

Experimenting with elements created by the Manhattan Project, researchers realized that they could create two different versions, or isotopes, of promethium, the sixty-first atom on the periodic table.

From The New Yorker

They include elements like gadolinium, lanthanum, cerium and promethium, and are vital in the production of cancer treatment drugs, smartphones and renewable energy technologies.

From The Guardian

Rare earth metals are a group of 17 elements - lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium - that appear in low concentrations in the ground.

From Reuters