The chemical element nickel has the atomic number 28 and the symbol Ni. It is a shiny, silvery-white metal and contains small amounts of gold. A transition metal with ductility and hardness is nickel. Although pure nickel is chemically reactive, it takes longer than usual for large particles to react with air because under normal conditions, a nickel oxide passivation layer grows on the surface to stop further corrosion. However, only trace amounts of pure natural nickel are found in the Earth's crust, typically in ultramafic rocks and the interiors of larger nickel-iron meteorites that have not come into contact with oxygen during their time outside the Earth's atmosphere.
Iron and meteoric nickel are often discovered together, indicative of their origin as essential byproducts of supernova nucleosynthesis. It is assumed that the outer and inner cores of the Earth are composed of iron-nickel combination.
B.C. By 3500 BC, people were using nickel (in the form of a natural meteoric nickel-iron alloy). Axel Fredrik Cronstedt, in the cobalt mines in Los, Hälsingland, Sweden, initially mistook the ore for a copper mineral and in 1751 first separated and categorized nickel as an element. The element's name is derived from Nickel, a mischievous figure in German mining folklore that represents the resistance of copper-nickel ores to copper refining. The iron ore limonite, which typically contains 1-2% nickel, is an economically important source of nickel. The naturally occurring silicate mineral assemblage known as pentlandite and garnierite are two important nickel ore minerals. Leading production sites include Norilsk, Russia; New Caledonia in the Pacific; and the Sudbury region of Canada.
The other three ferromagnetic elements are iron, cobalt and gadolinium. Nickel is one of these four substances. In terms of strength, between permanent magnets made of iron and rare earth magnets are Alnico magnets, which are partially nickel-based. The metal is mostly used in alloys and plating for corrosion resistance. Stainless steel accounts for more than 68% of global production. It is used in various applications such as 10 nickel and copper based alloys, 9% for plating, 7% for alloy steels, 3% for foundries and 4% for rechargeable batteries used in electric vehicles (EV). Although nickel is often used in coins, nickel allergies can occasionally be triggered by nickel-plated items.
Nickel is a substance used in a variety of specialized chemical industrial processes, including hydrogenation of fuel, production of cathodes for rechargeable batteries, pigments and metal surface treatments. Many bacteria and plants with enzymes whose active site is nickel accept nickel as an essential nutrient.
Physical and Atomic Properties of Nickel
Nickel is a highly polishable silvery-white metal with a pale gold hue. Only four elements—iron, cobalt, gadolinium, and that element—are ferromagnetic at or near ambient temperature. The temperature at which nickel ceases to be magnetic is known as the Curie temperature, which is 355 °C. The atomic radius of nickel is 0,124 nm, and its unit cell is a face-centered cube with a lattice parameter of 0,352 nm.
Pressures of at least 70 GPa are not sufficient to break this crystal structure. For transition metals, nickel has relatively high electrical and thermal conductivity and is hard, malleable and ductile. Due to the development and migration of dislocations, true bulk material never reaches the high compressive strength of 34 GPa expected for perfect crystals.
However, Ni nanoparticles have achieved this.
Disagreement over electron configuration
The two atomic electron configurations with relatively similar energies for nickel are [Ar] 3d8 4s2 and [Ar] 3d9 4s1. [Ar] represents the full argon core structure. There is some debate as to which configuration has the lower energy. [16] The electron configuration of nickel is given as [Ar] 4s2 3d8, often written as [Ar] 3d8 4s2. The Madelung energy ordering rule, which states that 4s is full before 3d, is compatible with this configuration. The empirical finding that the lowest energy state of the nickel atom is the 3d8 4s2 energy level – more specifically the 3d8(3F) 4s2 3F, J = 4 level – supports this theory.
However, due to the fine structure, each of these two configurations is split into several energy levels, and the two sets of energy levels overlap. Compared to Ar] 3d8 4s2, the average energy of states with [Ar] 3d9 4s1 is actually lower. As a result, the ground state configuration [Ar] 3d9 4s1 is listed in the academic literature on atomic calculations.
Isotopes of Nickel
Atomic weights of nickel isotopes range from 48 u (48Ni) to 82 u (82Ni). The five stable nickel isotopes found in nature are 58Ni, 60Ni, 61Ni, 62Ni, and 64Ni, with 58Ni having the highest natural abundance (68,077%).
Nickel-62 has the highest binding energy of any nuclide, with a nucleon binding energy of 8,7946 MeV. It has a higher binding energy than 56Fe and 58Fe, two common nuclides often mistakenly listed as having the highest binding energies. While this seems to indicate that nickel is the most common heavy element in the universe, iron is actually significantly more common due to nickel's high photointegration rate in stars.
The offspring of the long-extinct radioactive 60Fe is nickel-60 (half-life 2,6 million years). Given 60Fe's long half-life and persistence in solar system components, it is possible to see changes in 60Ni's isotopic composition. Consequently, the prevalence of 60Ni in foreign matter may shed light on the formation and early development of the Solar System.
There are at least 26 known radioisotopes of nickel; the most stable are 76.000Ni, 59Ni and 63Ni (56 days) with half-lives of 6 years. All other radioisotopes have half-lives less than 60 hours and often less than 30 seconds. Moreover, this element has a meta state.
Silicon burning results in the production of radioactive nickel-56, which is then released in significant quantities in type Ia supernovae. The light curves of these supernovas in the middle and late times are consistently shaped as 56Ni decays to cobalt-56 and then to iron-56 after electron capture. Nickel-59 is a cosmogenic radionuclide with a long half-life of 76.000 years.
Isotope geology has used 59Ni in several ways. 59Ni has been used to measure the amount of extraterrestrial dust in ice and sediments, as well as to date the age of meteorites on Earth. Nickel-110, whose half-life is currently estimated at 78 milliseconds, is thought to play an important role in the supernova nucleosynthesis of elements heavier than iron. The heavy element isotope with the highest known proton content is 1999Ni, found in 48. 48Ni is "double magic" with 28 protons and 20 neutrons, just like 28Ni with 50 protons and 78 neutrons. As a result, both are fairly stable for nuclei with such a significant proton-neutron imbalance.
Nuclear reactor support structures contain nickel-63, a contaminant. It is created through the neutron capture process of nickel-62. Small amounts have also been found near nuclear weapons test sites in the South Pacific.
Source: Wikipedia
Günceleme: 14/03/2023 13:14