who is credited with the discovery of oxygen

Discovery - 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..

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..

Discovery of the Cell - 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 pl..

. Thus the relative mass of such a particle = 1 amu and the absolute mass = 1.6 x 10 - 2 4 g. Because of their electrical neutrality, these particles were called neutrons We are now in a position of explain why the atomic mass of carbon is 12. It is now known that the carbon atom contains..

Discovery of Nitric Acid - 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 acid. S..

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..

How many 4 digit number secret codes can be framed for the credit card of a bank using the digits {1, 2, 3, 4, 5, 6, 7, 8, 9}? (repetition of a digit is allowed.) => 3,024 or 4 9 or 36 or 6,561..