Chemistry Reference Libraries

Page 5 of about 102 Articles
2009-07-09 17:47:41

Astatine is a radioactive chemical element. The symbol for Astatine is At and its atomic number is 85. Astatine is the heaviest halogen discovered. It was first produced by Dale R. Corson, Kenneth Ross Mackenzie, and Emilio Segrè in 1940. Although astatine is produced by radioactive decay in nature, it is typically found only in miniscule amounts due to its short half-life (the time it takes...

2009-07-09 17:39:38

Americium is a synthetic radioactive metallic element. The symbol for Americium is Am and the atomic number is 95. Americium is an actinide that was first isolated by Glenn T. Seaborg in 1944 while attacking plutonium with neutrons. It became the fourth transuranic (having an atomic number greater than 92) element to be discovered. It was named for the Americas. It is widely used in commercial...

2009-07-09 17:04:18

Actinium is a radioactive chemical element. The symbol for Actinium is Ac and the atomic number is 89. Actinium was discovered in 1899 by French chemist André-Louis Debierne. It was the first non-primordial radioactive element to be isolated. Actinium is amongst a group of 15 similar elements within the periodic table that make up the actinoid series. This substance was also independently...

Chemistry Main
2014-01-12 00:00:00

Chemistry is a physical science concerned with the composition, structure, and properties of matter. It also deals with the changes that matter undergoes during chemical reactions. It incorporates the studies of various atoms, molecules, crystals and other aggregates which can be combined or isolated and concepts of energy and entropy through which chemical processes occur. Modern chemistry...

de Ulloa Antonio
2013-03-16 00:00:00

Antonio de Ulloa was born on January 12, 1716 in Seville. Ulloa enlisted with the Spanish Navy in 1733. In 1735, he was sent to Ecuador as a member of the French Geodesic Mission. The mission, led by Pierre Bouguer, was organized by the French Academy of Sciences to measure a degree of the meridian at the equator. He stayed in Ecuador for 9 years until 1744, during this stint; he...

Palo Santo Bursera graveolens
2009-04-28 16:00:11

Bursera graveolens or Palo Santo is a tree indigenous to South America in Argetina, Paraguay, Boliva and coastal areas of Ecuador. Palo Santo means "holy wood" in English and belongs in the same family as frankincense and myrrh. Although it has been used in homeopathic medicine for years, most recently it is the extraction of essential oils that has put this plant in the spotlight....

Water strider
2005-09-09 07:46:52

The Water strider, (also known as: Skater, Pond Skater, Jesus Bug, Water Skeeter, water scooter, water skater, and Skimmer) is any of a number of predatory insects in the family Gerridae that rely on the surface tension of water to walk on top of it. They live on the surface of ponds, slow streams, marshes, and other quiet waters and can move very quickly (up to 1 m/s) over the surface of...

2005-09-08 12:01:05

Fireflies, also known as lightning bugs, are nocturnal, luminous beetles of the family Lampyridae. These names come from the fact that some species as adults emit flashes of light to attract mates, using special light-emitting organs in the abdomen. The enzyme luciferase acts on luciferin to stimulate light emission. This reaction is of scientific interest, and genes coding for these substances...

Borage Borago officinalis
2009-03-27 17:54:25

The annual herb, Borage, better known as Starflower, originated in Syria, but has been naturalized throughout the Mediterranean region, in addition to Asia Minor, Europe, North Africa and South America. The plant grows to heights of about 2 to 3 feet with bristly stems and leaves. The leaves themselves are alternately arranged and simple, and measure between 2 and 6 inches long. Five...

2005-05-26 12:19:41

Amphibole defines an important group of dark-colored rock-forming inosilicate minerals composed of double chain SiO4 tetrahedra linked at the vertices and generally containing ions of iron and/ or magnesium in their structures. In chemical composition and general characteristics they are very similar to the pyroxenes and, like them, fall into three series according to their system of...

Word of the Day
  • The deadly nightshade, Atropa Belladonna, which possesses stupefying or poisonous properties.
  • A sleeping-potion; a soporific.
  • To mutter deliriously.
The word 'dwale' comes from an Old English word meaning 'error, doubt, delusion.'