Ammolite
Ammolite is a rare and valuable opal -like organic gemstone found primarily along the eastern slopes of the Rocky Mountains of the United States and Canada . It is made of the fossil ized shells of ammonite s, which in turn are composed primarily of aragonite , the same mineral that m more
Atomic line filter Faraday filter designed, built and photographed by Jonas Hedin for making daytime LIDAR measurements at Arecibo Observatory.
An atomic line filter (ALF) is an advanced optical band-pass filter used in the physical science s for filtering electromagnetic radiation with precisi more
Technetium
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| Electron affinity || -53 kJ/mol
Technetium () is the lightest chemical element with no stable isotope . It has atomic number 43 and is given the symbol Tc. The chemical properties of this silvery grey, crystalline transition metal are inte more
Saffron
Saffron () is a spice derived from the flower of the saffron crocus (Crocus sativus), a species of crocus in the family Iridaceae . The flower has three stigma s, which are the distal ends of the plant's carpel s. Together with its style, the stalk connecting the stigmas to the rest of more
Joseph Priestley
(1794)
Joseph Priestley (13 March 1733 (old style ) – February 6 , 1804 ) was an 18th-century British theologian , Dissenting clergyman , natural philosopher , educator, and political theorist who published over 150 works. He is usually credited with the discovery of oxygen more