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Polystyrene sulfonates are a group of medications used to treat high blood potassium. [1] Effects generally take hours to days. [1] They are also used to remove potassium, calcium, and sodium from solutions in technical applications.
The Rutherford model is a name for the first model of an atom with a compact nucleus. The concept arose from Ernest Rutherford discovery of the nucleus. Rutherford directed the Geiger–Marsden experiment in 1909, which showed much more alpha particle recoil than J. J. Thomson's plum pudding model of the atom could explain. Thomson's model had ...
Thomson's model marks the moment when the development of atomic theory passed from chemists to physicists. While atomic theory was widely accepted by chemists by the end of the 19th century, physicists remained skeptical because the atomic model lacked any properties which concerned their field, such as electric charge, magnetic moment, volume, or absolute mass.
Using the following values, we will examine an example where an alpha particle passes through a gold atom: q g = positive charge of the gold atom = 79 q e = 1.26 × 10 −17 C; q a = charge of the alpha particle = 2 q e = 3.20 × 10 −19 C; v = speed of the alpha particle = 1.53 × 10 7 m/s; m = mass of the alpha particle = 6.64 × 10 −27 kg
Atomic numbers (Z) are a special case of charge numbers, referring to the charge number of an atomic nucleus, as opposed to the net charge of an atom or ion. The charge numbers for ions (and also subatomic particles ) are written in superscript, e.g., Na + is a sodium ion with charge number positive one (an electric charge of one elementary ...
The model is named after the Dutch physicist Hendrik Antoon Lorentz. It is a classical , phenomenological model for materials with characteristic resonance frequencies (or other characteristic energy scales) for optical absorption, e.g. ionic and molecular vibrations , interband transitions (semiconductors), phonons , and collective excitations.
The Bohr model of the atom. Rutherford deduced the existence of the atomic nucleus through his experiments but he had nothing to say about how the electrons were arranged around it. In 1912, Niels Bohr joined Rutherford's lab and began his work on a quantum model of the atom. [37]: 19
The Bohr model of the hydrogen atom (Z = 1) or a hydrogen-like ion (Z > 1), where the negatively charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus and where an electron jumps between orbits, is accompanied by an emitted or absorbed amount of electromagnetic energy (hν). [1]