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The most common decay mode of a radioisotope of zinc with a mass number lower than 66 is electron capture. The decay product resulting from electron capture is an isotope of copper. [45] n 30 Zn + e − → n 29 Cu + ν e. The most common decay mode of a radioisotope of zinc with mass number higher than 66 is beta decay (β −), which produces ...
Water is ~11% hydrogen by mass but ~67% hydrogen by atomic percent, and these numbers along with the complementary % numbers for oxygen in water, are the largest contributors to overall mass and atomic composition figures. Because of water content, the human body contains more oxygen by mass than any other element, but more hydrogen by atom ...
For example, 50 g of zinc will react with oxygen to produce 62.24 g of zinc oxide, implying that the zinc has reacted with 12.24 g of oxygen (from the Law of conservation of mass): the equivalent weight of zinc is the mass which will react with eight grams of oxygen, hence 50 g × 8 g/12.24 g = 32.7 g.
The atomicity of homonuclear molecule can be derived by dividing the molecular weight by the atomic weight. For example, the molecular weight of oxygen is 31.999, [3] while its atomic weight is 15.879; [4] therefore, its atomicity is approximately 2 (31.999/15.879 ≈ 2).
This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.
Naturally occurring zinc (30 Zn) is composed of the 5 stable isotopes 64 Zn, 66 Zn, 67 Zn, 68 Zn, and 70 Zn with 64 Zn being the most abundant (48.6% natural abundance).Twenty-eight radioisotopes have been characterised with the most stable being 65 Zn with a half-life of 244.26 days, and then 72 Zn with a half-life of 46.5 hours.
Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. [68] About 0.9% of the Sun's mass is oxygen. [19] Oxygen constitutes 49.2% of the Earth's crust by mass [69] as part of oxide compounds such as silicon dioxide and is the most abundant element by mass in the Earth's crust.
The chemists used an "atomic mass unit" (amu) scale such that the natural mixture of oxygen isotopes had an atomic mass 16, while the physicists assigned the same number 16 to only the atomic mass of the most common oxygen isotope (16 O, containing eight protons and eight neutrons).