when was the second gas discovered?
1868
Helium
Helium is named for the Greek Titan of the Sun, Helios. It was first detected as an unknown, yellow spectral line signature in sunlight, during a solar eclipse in 1868 by Georges Rayet, Captain C. T. Haig, Norman R. Pogson, and Lieutenant John Herschel, and was subsequently confirmed by French astronomer, Jules Janssen.
cause of joint pain in deep sea divers It is termed as "Decompression sickness”. It arises from underwater diving ascent. what are its different types? It was broadly classified in two categories. "Type I" for symptoms involving only the skin, musculoskeletal system, or lymphatic system, and "Type II" for symptoms where other organs, such as the central nervous system are effected. what results in it? It is caused by a reduction in ambient pressure that results in the formation of bubbles of inert gases within tissues of the body. is it caused by any particular gas? Yes a gas mixture of several such as nitrogen and helium to name a few.
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Helium [SEP] Introduction
As with any gas whose density differs from that of air, inhaling a small volume of helium temporarily changes the timbre and quality of the human voice. In scientific research, the behavior of the two fluid phases of helium-4 (helium I and helium II) is important to researchers studying quantum mechanics (in particular the property of superfluidity) and to those looking at the phenomena, such as superconductivity, produced in matter near absolute zero.