Venom - Chemistry Encyclopedia
It may be tempting to equate the concept of venom with poison, but to do so would be inaccurate. Many plants, for example, are poisonous but present no harm to humans because they have learned not to eat them.
Water - Chemistry Encyclopedia
If a person knows nothing else about chemistry, he or she will likely know that water is H2O. The chemical formula for water is common knowledge, used in advertisements, elementary school science classes, and casual conversation.
Water Pollution - Chemistry Encyclopedia
Water pollution occurs when undesirable foreign substances are introduced into natural water. The substances may be chemical or biological in nature.
Water Quality - Chemistry Encyclopedia
Next to a supply of air, nothing is so essential to life as a supply of high-quality water. We drink it, cook our food in it, use it as a source of energy, and lift a hundred pounds or so of it each time we stand up.
Xenon - Chemistry Encyclopedia
Ytterbium - Chemistry Encyclopedia
Yttrium - Chemistry Encyclopedia
Zeolites - Chemistry Encyclopedia
Zeolites are a large group of natural and synthetic hydrated aluminum silicates. They are characterized by complex three-dimensional structures with large, cagelike cavities that can accommodate sodium, calcium, or other cations (positively charged atoms or atomic clusters); water molecules; and even small organic molecules.
Zinc - Chemistry Encyclopedia
Zirconium - Chemistry Encyclopedia
Zwitterions - Chemistry Encyclopedia
Zwitterions (the word is derived from the German for "hybrid ion") are ions that are electrically neutral overall but contain nonadjacent regions of positive and negative charges; they are sometimes referred to as "dipolar ions." The best-known examples of zwitterions are the free amino acids found in cells.
Van't Hoff, Jacobus Hendricus - Chemistry Encyclopedia
Volta, Alessandro - Chemistry Encyclopedia
Until the late 1700s static electricity was the only known form of electricity. Alessandro Volta, born in Como, Italy, is best known for discovering current electricity and for developing the voltaic pile, which became an invaluable tool in electrochemistry.
Waksman, Selman Abraham - Chemistry Encyclopedia
Selman Waksman changed the course of medical history while investigating how soil microbes defended themselves against invaders. He and coworkers isolated twenty-two new defensive compounds produced by soil microbes and in the process discovered streptomycin, the first antibiotic effective against tuberculosis.
Watson, James Dewey - Chemistry Encyclopedia
The American biochemist James Dewey Watson was a discoverer of the double-helical structure of the deoxyribonucleic acid molecule.
Weizmann, Chaim - Chemistry Encyclopedia
One of the few who have achieved success in two disparate fields, chemist and statesman Chaim Weizmann was born on November 17, 1874, in the small town of Motol, Russia—part of what was known as the Pale of Settlement, an area where Jewish families were allowed to live. Beginning at age four he attended a religious school in which classes were conducted in Yiddish.
Werner, Alfred - Chemistry Encyclopedia
Willstätter, Richard Martin - Chemistry Encyclopedia
Wöhler, Friedrich - Chemistry Encyclopedia
German chemist Friedrich Wöhler, who isolated the element aluminum.
Woodward, Robert Burns - Chemistry Encyclopedia
Yalow, Rosalyn Sussman - Chemistry Encyclopedia
Rosalyn Sussman Yalow was awarded the Nobel Prize in physiology or medicine in 1977 for her pioneering work in developing the technique known as radioimmunoassay (RIA), a method first applied to the measurement of concentrations in blood of the hormone insulin. Subsequently the use of RIA was extended to include the detection and quantification of a wide range of substances of biological interest, including other hormones, serum proteins, enzymes, viruses, and tumor antigens.
Yukawa, Hideki - Chemistry Encyclopedia
Zsigmondy, Richard Adolf - Chemistry Encyclopedia
Richard Zsigmondy received the 1925 Nobel Prize in chemistry for his elucidation of the nature of colloidal suspensions. With Henry Siedentopf (1872–1940), he invented, used, and promoted the ultramicroscope.