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Xe is the heaviest noble gas in the Earth's atmosphere. It has seven stable isotopes (126 Xe, 128 Xe, 129 Xe, 130 Xe, 131 Xe, 132 Xe, 134 Xe) and two isotopes (124 Xe, 136 Xe) with long-lived half-lives. Xe has four synthetic radioisotopes with very short half-lives, usually less than one month. Xenon-129 can be used to examine the early ...
[13] [86] The reduced amount of dissolved gas in the body means that fewer gas bubbles form during the decrease in pressure of the ascent. Another noble gas, argon, is considered the best option for use as a drysuit inflation gas for scuba diving. [87] Helium is also used as filling gas in nuclear fuel rods for nuclear reactors. [88] Goodyear Blimp
The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface (both lands and oceans), known collectively as air, with variable quantities of suspended aerosols and particulates (which create weather features such as clouds and hazes), all retained by Earth's gravity.
This list is sorted by boiling point of gases in ascending order, but can be sorted on different values. "sub" and "triple" refer to the sublimation point and the triple point, which are given in the case of a substance that sublimes at 1 atm; "dec" refers to decomposition. "~" means approximately.
Argon is the third most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv).
Radon concentrations found in natural environments are much too low to be detected by chemical means. A 1,000 Bq/m 3 (relatively high) concentration corresponds to 0.17 picogram per cubic meter (pg/m 3). The average concentration of radon in the atmosphere is about 6 × 10 −18 molar percent, or about 150 atoms in each milliliter of air. [75]
Nitrogen-13 and oxygen-15 are produced in the atmosphere when gamma rays (for example from lightning) knock neutrons out of nitrogen-14 and oxygen-16: 14 N + γ → 13 N + n 16 O + γ → 15 O + n. The nitrogen-13 produced as a result decays with a half-life of 9.965(4) min to carbon-13, emitting a positron.
In Earth's atmosphere, the ratio of 3 He to 4 He is 1.343(13) × 10 −6. [5] However, the isotopic abundance of helium varies greatly depending on its origin. In the Local Interstellar Cloud , the proportion of 3 He to 4 He is 1.62(29) × 10 −4 , [ 6 ] which is ~121 times higher than in Earth's atmosphere.