He was also the person who first identified silicon, selenium, thorium, and serium.
It wasn't practical to take the thorium rock in for a landing.
The substance ranking next in radio-activity to radium is thorium.
The mantle is made by dipping a cylinder of cotton net into a solution of nitrate of thorium and cerium, containing 99 per cent.
thorium and uranium, proportionality of, in older rocks, 26.
They put the thorium block which contained the plutonium into the hole, the plutonium facing outward.
They would be compared with a chunk of thorium of the same size.
Nothing is, on the other hand, known respecting the origin of uranium or thorium—the parent radioactive bodies.
Emperor of all the metal molecules and king of the thorium spurs.
Compounds of thorium, similar to those used for incandescent mantles, were found to have the same properties.
thorium tho·ri·um (thôr'ē-əm)
A radioactive metallic element that is used in magnesium alloys; its longest-lived isotope, Th 232, has a half-life of 1.41 × 1010 years. Atomic number 90; atomic weight 232.038; approximate melting point 1,750°C; approximate boiling point 4,800°C; approximate specific gravity 11.7; valence 4.
A silvery-white, radioactive metallic element of the actinide series. It is used for fuel in some nuclear reactors and for improving the high-temperature strength of magnesium alloys. The only naturally occurring isotope of thorium, Th 232, is also its most stable, having a half-life of 14.1 billion years. Atomic number 90; atomic weight 232.038; approximate melting point 1,750°C; approximate boiling point 4,500°C; approximate specific gravity 11.7; valence 4. See Periodic Table.