• a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
Example sentence
• The balloon floated in the air due to the presence of helium.
• a soft grey malleable metallic element that resembles tin but discolors on exposure to air; it is highly toxic and is used in rodent and insect poisons; occurs in zinc blende and some iron ores
Example sentence
• She was diagnosed with thallium poisoning after experiencing severe nausea and dizziness.
• a white metallic element that burns with a brilliant light; the fifth most abundant element in the earth's crust; an important component of most plants and animals
Example sentence
• Milk and dairy products are excellent sources of calcium.
• 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 silvery soft waxy metallic element of the alkali metal group; occurs abundantly in natural compounds (especially in salt water); burns with a yellow flame and reacts violently in water; occurs in sea water and in the mineral halite (rock salt)
Example sentence
• Table salt is a compound made up of sodium and chlorine.
• a light silver-white ductile bivalent metallic element; in pure form it burns with brilliant white flame; occurs naturally only in combination (as in magnesite and dolomite and carnallite and spinel and olivine)
Example sentence
• Dietary sources of magnesium include nuts, seeds, and leafy green vegetables.
• 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 grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals; used in filaments for its ready emission of electrons
Example sentence
• The name hafnium derives from Hafnia, the Latin name for Copenhagen.
• 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.
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.
