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Oxygen-13 is an unstable isotope, with 8 protons and 5 neutrons. It has spin 3/2−, and half-life 8.58(5) ms. Its atomic mass is 13.024 815 (10) Da. It decays to nitrogen-13 by electron capture, with a decay energy of 17.770(10) MeV. Its parent nuclide is fluorine-14.
In ice cores, mainly Arctic and Antarctic, the ratio of 18 O to 16 O (known as δ 18 O) can be used to determine the temperature of precipitation through time.Assuming that atmospheric circulation and elevation has not changed significantly over the poles, the temperature of ice formation can be calculated as equilibrium fractionation between phases of water that is known for different ...
Oxygen-17 (17 O) is a low-abundance, natural, stable isotope of oxygen (0.0373% in seawater; approximately twice as abundant as deuterium).. As the only stable isotope of oxygen possessing a nuclear spin (+5/2) and a favorable characteristic of field-independent relaxation in liquid water, 17 O enables NMR studies of oxidative metabolic pathways through compounds containing 17 O (i.e ...
Thus, for example, there are three main isotopes of carbon. All carbon atoms have 6 protons, but they can have either 6, 7, or 8 neutrons. Since the mass numbers of these are 12, 13 and 14 respectively, said three isotopes are known as carbon-12, carbon-13, and carbon-14 (12 C, 13 C, and 14 C).
The darker more stable isotope region departs from the line of protons (Z) = neutrons (N), as the element number Z becomes larger. This is a list of chemical elements by the stability of their isotopes. Of the first 82 elements in the periodic table, 80 have isotopes considered to be stable. [1] Overall, there are 251 known stable isotopes in ...
It is much more reactive with common organic molecules than is normal (triplet) molecular oxygen. In nature, singlet oxygen is commonly formed from water during photosynthesis, using the energy of sunlight. [38]
H or T), which has two neutrons. Oxygen also has three stable isotopes, with 16 O present in 99.76%, 17 O in 0.04%, and 18 O in 0.2% of water molecules. [78] Deuterium oxide, D 2 O, is also known as heavy water because of its higher density. It is used in nuclear reactors as a neutron moderator.
Of the 94 natural elements, eighty have a stable isotope and one more has an almost-stable isotope (with a half-life of 2.01×10 19 years, over a billion times the age of the universe). [15] [b] Two more, thorium and uranium, have isotopes undergoing radioactive decay with a half-life comparable to the age of the Earth.