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Sulfur ( 16 S) has 23 known isotopes with mass numbers ranging from 27 to 49, four of which are stable: 32 S (95.02%), 33 S (0.75%), 34 S (4.21%), and 36 S (0.02%). The preponderance of sulfur-32 is explained by its production from carbon-12 plus successive fusion capture of five helium-4 nuclei, in the so-called alpha process of exploding type ...
540 Chemistry. 540 Chemistry and allied sciences; 541 Physical chemistry; 542 Techniques, procedures, apparatus, equipment, materials; 543 Analytical chemistry; 544 No longer used — formerly "Qualitative analysis" 545 No longer used — formerly "Quantitative analysis" 546 Inorganic chemistry; 547 Organic chemistry; 548 Crystallography; 549 ...
In statistics, the 68–95–99.7 rule, also known as the empirical rule, and sometimes abbreviated 3sr, is a shorthand used to remember the percentage of values that lie within an interval estimate in a normal distribution: approximately 68%, 95%, and 99.7% of the values lie within one, two, and three standard deviations of the mean, respectively.
In modern chemistry, the p stands for "the negative decimal logarithm of", and is used in the term pK a for acid dissociation constants, [11] so pH is "the negative decimal logarithm of H + ion concentration", while pOH is "the negative decimal logarithm of OH- ion concentration".
The Avogadro constant, commonly denoted N A [1] or L, [2] is an SI defining constant with an exact value of 6.022 140 76 × 10 23 mol −1 (reciprocal moles). [3] [4] It is defined as the number of constituent particles (usually molecules, atoms, or ions) per mole and used as a normalization factor in the amount of substance in a sample.
Isotopes of silver (47Ag) Naturally occurring silver ( 47 Ag) is composed of the two stable isotopes 107 Ag and 109 Ag in almost equal proportions, with 107 Ag being slightly more abundant (51.839% natural abundance ). Notably, silver is the only element with all stable istopes having nuclear spins of 1/2. Thus both 107 Ag and 109 Ag nuclei ...
In June 2024, the Futures section of nature.com published a fictional Wikipedia Talk page under the title "Plastic-eating fungus caused doomsday [2][3] A collaborative effort" by Emma Burnett. [302] The Talk page concerned a (fictional) article describing unintended consequences the release of a plastic-eating fungus to clean up an oil spill.
South Korea's real GDP expanded by an average of more than 8 percent per year, [44] from US$2.7 billion in 1962 [45] to US$230 billion in 1989, [46] breaking the trillion dollar mark in the early 2000s. Nominal GDP per capita grew from $103.88 in 1962 [47] to $5,438.24 in 1989, [48] reaching the $20,000 milestone in 2006.