• (microbiology) single-celled or noncellular spherical or spiral or rod-shaped organisms lacking chlorophyll that reproduce by fission; important as pathogens and for biochemical properties; taxonomy is difficult; often considered to be plants
Example sentence
• A single bacterium can multiply into millions within a few hours.
• a brittle silver-white metalloid element that is related to selenium and sulfur; it is used in alloys and as a semiconductor; occurs mainly as tellurides in ores of copper and nickel and silver and gold
Example sentence
• The melting point of tellurium is approximately 449.5 degrees Celsius.
• a light strong grey lustrous corrosion-resistant metallic element used in strong lightweight alloys (as for airplane parts); the main sources are rutile and ilmenite
Example sentence
• Many aircraft and spacecraft use titanium for its durability.
• a radioactive metallic element that is similar to tellurium and bismuth; occurs in uranium ores but can be produced by bombarding bismuth with neutrons in a nuclear reactor
• a soft silvery-white tetravalent radioactive metallic element; isotope 232 is used as a power source in nuclear reactors; occurs in thorite and in monazite sands
Example sentence
• The abundance of thorium in the Earth's crust is about four times that of uranium.
• a permanent executive committee in socialist countries that has all the powers of some larger legislative body and that acts for it when it is not in session
Example sentence
• The presidium of the committee convened to discuss the budget proposal.
• a light soft silver-white metallic element of the alkali metal group; oxidizes rapidly in air and reacts violently with water; is abundant in nature in combined forms occurring in sea water and in carnallite and kainite and sylvite
• a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles (Md is the current symbol for mendelevium but Mv was formerly the symbol)
Example sentence
• The element mendelevium is named after the Russian chemist Dmitri Mendeleev.
• a solid silvery grey radioactive transuranic element whose atoms can be split when bombarded with neutrons; found in minute quantities in uranium ores but is usually synthesized in nuclear reactors; 13 isotopes are known with the most important being plutonium 239
Example sentence
• The United States has stockpiled tons of plutonium.
• a soft silvery metallic element of the alkali metal group; burns in air and reacts violently in water; occurs in carnallite and lepidolite and pollucite
Example sentence
• The rubidium atom has 37 electrons and 37 protons.
Note: This list has been curated by our developer and author and fine-tuned since 2016 with manual additions, exclusions and rankings. Thousands of user contributions from rappers, singers, songwriters and poets have also been used for accuracy.
