mesothorium

noun

meso·thorium | \ ¦me|zō, ¦mē|, |sō+\

Definition of mesothorium

: either of two radioactive products intermediate between thorium and radiothorium in the thorium series or a mixture of the two products obtained usually from thorium minerals (as monazite sand) and used as a substitute for radium especially in luminous paints:

a : an isotope of radium

— called also mesothorium 1

—symbol MsTh₁ or Ra²²⁸

b : an isotope of actinium

— called also mesothorium 2

—symbol MsTh₂ or Ac²²⁸

Keep scrolling for more

Comments on mesothorium

What made you want to look up mesothorium? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

peer-to-peer

using a distributed computer network

Test Your Vocabulary

Time Traveler Quiz: Which Word Came First?

Which came first?

sarcastic snarky

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ