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Fluorine is a chemical element; it has symbol F and atomic number 9. It is the lightest halogen [ note 1 ] and exists at standard conditions as pale yellow diatomic gas. Fluorine is extremely reactive as it reacts with all other elements except for the light inert gases .
Fluoride (/ ˈ f l ʊər aɪ d, ˈ f l ɔːr-/) [3] is an inorganic, monatomic anion of fluorine, with the chemical formula F − (also written [F] −), whose salts are typically white or colorless. Fluoride salts typically have distinctive bitter tastes, and are odorless.
The f-number N is given by: = where f is the focal length, and D is the diameter of the entrance pupil (effective aperture).It is customary to write f-numbers preceded by "f /", which forms a mathematical expression of the entrance pupil's diameter in terms of f and N. [1]
In probability theory and statistics, the F-distribution or F-ratio, also known as Snedecor's F distribution or the Fisher–Snedecor distribution (after Ronald Fisher and George W. Snedecor), is a continuous probability distribution that arises frequently as the null distribution of a test statistic, most notably in the analysis of variance (ANOVA) and other F-tests.
The formula for the one-way ANOVA F-test statistic is =, or =. The "explained variance", or "between-group variability" is = (¯ ¯) / where ¯ denotes the sample mean in the i-th group, is the number of observations in the i-th group, ¯ denotes the overall mean of the data, and denotes the number of groups.
Hydrogen fluoride (fluorane) is an inorganic compound with chemical formula H F.It is a very poisonous, colorless gas or liquid that dissolves in water to yield hydrofluoric acid.
In physical chemistry, the Faraday constant (symbol F, sometimes stylized as ℱ) is a physical constant defined as the quotient of the total electric charge (q) by the amount (n) of elementary charge carriers in any given sample of matter: F = q/n; it is expressed in units of coulombs per mole (C/mol).
The F-gas Regulation adopts an approach based on containment and recovery of F-gases as well as imposing obligations on reporting, training and labeling on those using F-gases. On 26 September 2011, the Commission issued a report on the application, effects and adequacy of the Regulation, drawing from the results of an analytical study it ...