phlogiston, he didn't realise that he had prepared a new element, and thought that he had managed to prepare air free from phlogiston. However, he was the first to isolate oxygen, even if he didn't realise what he had: |
phlogiston, he didn't realise that he had prepared a new element, and thought that he had managed to prepare air free from phlogiston ("de-phlogisticated air"). However, he was the first to isolate oxygen, even if he didn't realise what he had: |
Refrigeration? technology advanced considerably during the 19th cnntury, to the point where it was possible to liquefy atmospheric gases. A curious observation was made: Nitrogen prepared by chemical means from its compounds had a slightly lower molecular weight than nitrogen prepared by liquefaction from air. This was attributed as being due to the presence of a previously unsuspected gas, christened argon. This gas was the first representative found of a previously unsuspected new group in the periodic table, first known as the inert gases, now more commonly known as the noble gases. |
Refrigeration? technology advanced considerably during the 19th century, to the point where it was possible to liquefy atmospheric gases. A curious observation was made: Nitrogen prepared by chemical means from its compounds had a slightly lower molecular weight than nitrogen prepared by liquefaction from air. This was attributed as being due to the presence of a previously unsuspected gas, christened argon. This gas was the first representative found of a previously unsuspected new group in the periodic table, first known as the inert gases, now more commonly known as the noble gases. |
The discovery of Technetium finally filled in a puzzling gap in the periodic table, and the discovery that there were no stable isotopes of technetium explained its absence on earth: its 4.2 million years half-life meant that none remained from the time of formation of the Earth. |
The discovery of Technetium finally filled in a puzzling gap in the periodic table, and the discovery that there were no stable isotopes of technetium explained its absence on earth: its 4.2 million years half-life meant that none remained from the time of formation of the Earth. |