Search results
Results From The WOW.Com Content Network
Gallium is a chemical element; it has the symbol Ga and atomic number 31. Discovered by the French chemist Paul-Émile Lecoq de Boisbaudran in 1875, [11] gallium is in group 13 of the periodic table and is similar to the other metals of the group (aluminium, indium, and thallium). Elemental gallium is a relatively soft, silvery metal at ...
The d-block contraction (sometimes called scandide contraction[1]) is a term used in chemistry to describe the effect of having full d orbitals on the period 4 elements. The elements in question are gallium, germanium, arsenic, selenium, bromine, and krypton [citation needed]. Their electronic configurations include completely filled d orbitals ...
Germanium is a chemical element; it has symbol Ge and atomic number 32. It is lustrous, hard-brittle, grayish-white and similar in appearance to silicon. It is a metalloid (more rarely considered a metal) in the carbon group that is chemically similar to its group neighbors silicon and tin. Like silicon, germanium naturally reacts and forms ...
Electron shell. In chemistry and atomic physics, an electron shell may be thought of as an orbit that electrons follow around an atom 's nucleus. The closest shell to the nucleus is called the "1 shell" (also called the "K shell"), followed by the "2 shell" (or "L shell"), then the "3 shell" (or "M shell"), and so on further and further from ...
So the expansion can be written as: = where K = m 1 b 1 + m 2 b 2 + m 3 b 3 for any set of integers (m 1, m 2, m 3). From this theory, an attempt can be made to predict the band structure of a particular material, however most ab initio methods for electronic structure calculations fail to predict the observed band gap.
In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863. Major periodic trends include atomic radius, ionization energy, electron affinity, electronegativity ...
For example, chlorine (element 17), with electron configuration 1s 2 2s 2 2p 6 3s 2 3p 5, has 17 protons and 10 inner shell electrons (2 in the first shell, and 8 in the second) so: Core charge = 17 − 10 = +7. A core charge is the net charge of a nucleus, considering the completed shells of electrons to act as a 'shield.'
Germanium also reacts with molten caustic soda to yield sodium germanate Na 2 GeO 3 and hydrogen gas. [307] It melts at 938 °C. Germanium is a semiconductor with an electrical conductivity of around 2 × 10 −2 S•cm −1 [306] and a band gap of 0.67 eV. [308]