English chemist who received the Nobel prize in chemistry in 1958 for his discovery of the chemical structure of proteins, particularly insulin. He won the prize again in 1980 for studies concerning the determination of the base sequences of nucleic acids.
For a complete bio double click Fred sanger or Fredrick Sanger on this page.
The liquid element mercury was isolated by the ancient Chinese and the Egyptians, probably from the mineral cinnabar (mercuric sulfide). Mercury was also refined and used in Mesoamerica by the Maya, independently of the Chinese discovery.
While some early users imagined that it had medicinal properties, the opposite was true because the metal is a toxic poison.
In past societies, the mercury ore (cinnabar) was valued for its red colour. When cinnabar is heated, it reverts to metallic mercury. Mercury gave silver and gold objects a beautiful shine - as well as poisoning the miners, refiners and owners of the objects.
The original name for the element was "quicksilver" (for its shine and liquid form). The current name may reference the Greek God, Mercury, who was known for his shiny helmet and being fleet of foot. Its chemical symbol Hg comes from the Latin hydrargyrum ("silver water").
Mercury was identified as a chemical element by French scientist Antoine Lavoisier (1743-1794).
Because the ancients had no resources that would identify Mercury as a dangerous and deadly ore, it probably caused the death of many people, especially those who used it as a medicine. In more modern times, dentists used mercury in tooth fillings. But in the mid 20th century, dentists stopped using mercury as part of an amalgam for filling teeth.
Researchers in the 16th century itself has predicted the existence of the North Pole. Several explorers tried to reach the North Pole in the 18th century. In 1827, a British naval officer named William Edward Parry tried, but was forced to turn back.Later in 1871, an expedition led by American Charles Hall had also failed.In 1895 Norwegian explorers Fridtjof Nansen and Fredrik Hjalmar Johansen got to 86 degrees 14' North prior to being forced back. The Italian whaler Stella Polare got to 86 degrees and 34'. In the first part of 19th century a man by name Frederick Cook who was an American declared that he reached the pole on April 21, 1908. But his expedition was not recognized due to lack of sufficient evidence. Later an American naval engineer Robert Peary claimed he reached the North Pole on April 6, 1909. His expedition is still under dispute. One of the objections was that none of Peary's men were trained for navigation. His expedition is also said to be 3 times faster than any other expeditions to the pole.
Crayons are made from paraffin which is a type of wax, and color pigments. Paraffin is made from extracting chemicals from wood, coal or petroleum. Pigments come from natural or artificial made substances which means they can be found in the Earth, minerals and/or made in factories.