^ Senga, Ryosuke Suenaga, Kazu (2015).Ullmann's Encyclopedia of Industrial Chemistry. "Precision Measurements of Crystals of the Alkali Halides". "Optical properties and electronic structure of alkali halides by thermoreflectivity". Journal of the Physical Society of Japan. Solubilities of inorganic and organic compounds c. Water accelerates the oxidation process, and iodide can also produce I 2 by photooxidation, therefore for maximum stability sodium iodide should be stored under dark, low temperature, low humidity conditions. I 2 and I − complex to form the triiodide complex, which has a yellow color, unlike the white color of sodium iodide. Iodides (including sodium iodide) are detectably oxidized by atmospheric oxygen (O 2) to molecular iodine (I 2). Solubility of NaI (g NaI/kg of solvent at 25 ☌) Sodium iodide exhibits high solubility in some organic solvents, unlike sodium chloride or even bromide: After experiments on rabbits and dogs he settled upon sodium iodide as the best medium. Radiocontrast Īntónio Egas Moniz searched for a radiocontrast agent for cerebral angiography. The wavelength of maximum emission is 415 nm. Sodium iodide can be used both as single crystals and as polycrystals for this purpose. Crystals with a higher level of doping are used in X-ray detectors with high spectrometric quality. Fine-tuning of some parameters (i.e., radiation hardness, afterglow, transparency) can be achieved by varying the conditions of the crystal growth. The crystals are usually coupled with a photomultiplier tube, in a hermetically sealed assembly, as sodium iodide is hygroscopic. NaI(Tl) is the most widely used scintillation material. Sodium iodide activated with thallium, NaI(Tl), when subjected to ionizing radiation, emits photons (i.e., scintillate) and is used in scintillation detectors, traditionally in nuclear medicine, geophysics, nuclear physics, and environmental measurements. Some radioactive iodide salts of sodium, including Na 125I and Na 131I, have radiopharmaceutical uses for thyroid cancer and hyperthyroidism or as radioactive tracer in imaging (see Isotopes of iodine > Radioiodines I-123, I-124, I-125, and I-131 in medicine and biology). This method, the Finkelstein reaction, relies on the insolubility of sodium chloride in acetone to drive the reaction: R–Cl + NaI → R–I + NaCl Nuclear medicine Sodium iodide is used for conversion of alkyl chlorides into alkyl iodides. Therefore, there are various non-equivalent definitions of atomic radius.Monatomic NaI chains grown inside double-wall carbon nanotubes.
#SODIUM ELEMENT SYBOLE FREE#
However, this assumes the atom to exhibit a spherical shape, which is only obeyed for atoms in vacuum or free space. The atomic radius of a chemical element is a measure of the distance out to which the electron cloud extends from the nucleus. It must be noted, atoms lack a well-defined outer boundary. The atomic radius of Sodium atom is 166pm (covalent radius). Note that, each element may contain more isotopes, therefore this resulting atomic mass is calculated from naturally-occuring isotopes and their abundance. The atomic mass is carried by the atomic nucleus, which occupies only about 10 -12 of the total volume of the atom or less, but it contains all the positive charge and at least 99.95% of the total mass of the atom. The atomic mass or relative isotopic mass refers to the mass of a single particle, and therefore is tied to a certain specific isotope of an element. Mass numbers of typical isotopes of Sodium are 23. Isotopes are nuclides that have the same atomic number and are therefore the same element, but differ in the number of neutrons. The difference between the neutron number and the atomic number is known as the neutron excess: D = N – Z = A – 2Z.įor stable elements, there is usually a variety of stable isotopes. Neutron number plus atomic number equals atomic mass number: N+Z=A. The total number of neutrons in the nucleus of an atom is called the neutron number of the atom and is given the symbol N. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10 -19 coulombs. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. Sodium is a chemical element with atomic number 11 which means there are 11 protons in its nucleus. Atomic Number – Protons, Electrons and Neutrons in Sodium
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