Search results
Results from the WOW.Com Content Network
Bromine is a chemical element; it has symbol Br and atomic number 35. It is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Its properties are intermediate between those of chlorine and iodine .
In chemistry, the bromine number is the amount of bromine (Br 2) in grams absorbed by 100 g of a sample.The bromine number was once used as a measure of aliphatic unsaturation in gasoline and related petroleum samples, but this assay has fallen into disuse with the introduction of spectroscopic and chromatographic analyses.
Bromine (35 Br) has two stable isotopes, 79 Br and 81 Br, and 35 known radioisotopes, the most stable of which is 77 Br, with a half-life of 57.036 hours.. Like the radioactive isotopes of iodine, radioisotopes of bromine, collectively radiobromine, can be used to label biomolecules for nuclear medicine; for example, the positron emitters 75 Br and 76 Br can be used for positron emission ...
For other isotopes, the isotopic mass is usually within 0.1 u of the mass number. For example, 35 Cl (17 protons and 18 neutrons) has a mass number of 35 and an isotopic mass of 34.96885. [7] The difference of the actual isotopic mass minus the mass number of an atom is known as the mass excess, [8] which for 35 Cl is –0.03115.
{{Infobox element}}; labels & notes: (Image) GENERAL PROPERTIES Name Symbol Pronunciation (data central) Alternative name(s) Allotropes Appearance <element> IN THE PERIODIC TABLE Periodic table Atomic number Standard atomic weight (data central) Element category (also header bg color) (sets header bg color, over 'series='-color) Group Period ...
The mass number of an element, A, is the number of nucleons (protons and neutrons) in the atomic nucleus. Different isotopes of a given element are distinguished by their mass number, which is written as a superscript on the left hand side of the chemical symbol (e.g., 238 U). The mass number is always an integer and has units of "nucleons".
CAS Number. anhydrous: 7647-15-6 ... Molar mass: 102.894 g·mol −1 Appearance White powder, ... Sodium bromide can be used as a source of the chemical element bromine.
Industrially, it is mainly produced by the reaction of hydrogen gas with bromine gas at 200–400 °C with a platinum catalyst. However, reduction of bromine with red phosphorus is a more practical way to produce hydrogen bromide in the laboratory: [2] 2 P + 6 H 2 O + 3 Br 2 → 6 HBr + 2 H 3 PO 3 H 3 PO 3 + H 2 O + Br 2 → 2 HBr + H 3 PO 4