discovery of oxygen

Two scientists, Carl Scheele of Sweden and Joseph Priestly of England working independently, discovered oxygen. They published their discovery in 1777. Scheele obtained oxygen by heating potassium nitrate and mercuric oxide and called it "Fire Air". Priestley cal..

Two scientists, Carl Scheele of Sweden and Joseph Priestly of England working independently, discovered oxygen. They published their discovery in 1777. Scheele obtained oxygen by heating potassium nitrate and mercuric oxide and called it "Fire Air". Priestley called i..

The Swedish chemist Carl Wilhelm Scheele first prepared chlorine in 1770 by treating hot concentrated hydrochloric acid with manganese dioxide. Unfortunately, he thought that it was an oxygen containing compound and did not recognize it as an element. After more than 30 years, th..

The history of the discovery of cells dates back to the 17 t h century and is closely associated with the history of the invention of microscopes. An Italian microscopist Marcello Malpighi studied the structure of some plants and proposed the idea that plants are composed of tiny structur..

The credit of discovery of first noble gas argon goes to Henry Cavendish who performed number of experiments to study the composition of air. He found that air is approximately 79 per cent nitrogen and 21 per cent oxygen by volume. Traces of carbon dioxide and water vapor were ..

Johann Glauber (1604-1668) prepared nitric acid by heating nitre with concentrated sulphuric acid and then condensing the vapour. While Henry Cavendish determined the composition of nitric acid, Lavoisier proved that oxygen is present in nitric aci..

Ernest Rutherford, an energetic New Zealander working in England, was studying the properties of particles spontaneously emitted by radioactive substances. Of particular interest was a positively charged, relatively heavy emission named alpha particle. Quantities of such particles are emitted by c..

Atoms and Nuclei..

In 1896, the phenomenon of radioactivity was accidentally discovered by French scientist Henri Becquerel. He was performing experiments with uranium compounds. He accidentally placed a crystal of potassium uranyl sulphate over photographic plate wrapped with usual black paper. On developing the p..

The table shows the number of viewers of different T.V channels in U.S.A. Choose the appropriate box-and-whisker plot for the data and find the mean number of T.V viewers. Number of viewers of different T.V channels in U.S Channel Number of viewers (in millions) Discovery 20 Star Sports 1..