Search results
This was a foundational discovery that eventually changed the whole of chemistry and physics. He is credited with discovering the element thallium, announced in 1861, with the help of spectroscopy. He was also the first to describe the spectrum of terrestrial helium, in 1865.
Jun 13, 2024 · Sir William Crookes was a British chemist and physicist noted for his discovery of the element thallium and for his cathode-ray studies, fundamental in the development of atomic physics. After studying at the Royal College of Chemistry, London, Crookes became superintendent of the meteorological.
- The Editors of Encyclopaedia Britannica
Jun 8, 2018 · The English chemist and physicist Sir William Crookes (1832-1919) discovered the element thallium and invented the radiometer, the spinthariscope, and the Crookes tube. William Crookes was born in London on June 17, 1832.
Crookes was primarily a chemist, his research topics ranged from improving early photographic processes to extracting precious metals from ores, and in 1861 he discovered the element thallium. From 1867 he became interested in spiritualism which affected his views on science.
Crookes was very innovative in his investigations with vacuum tubes and designed a variety of different types to be used in his experimental work. One of the most famous is the Maltese cross Crookes tube, which he used to demonstrate that cathode rays travel in straight lines.
With the introduction of spectrum analysis by R.W. Bunsen and G.R. Kirchhoff, Crookes applied the new technique to the study of selenium compounds. In 1861 he discovered thallium in some seleniferous deposits, and exhibited a sample of it at the Great Exhibition of 1862.
Sir William Crookes, O.M., F.R.S., born in London on 17 June 1832 is most noted for his discovery of thallium and his research in cathode rays. His scientific career began in 1848 at the age of fifteen when he entered the Royal College of Chemistry, London, under A.W. von Hofmann.
