The discovery of the 118 chemical elements known to exist as of 2023 is presented in chronological order. The elements are listed generally in the order in which each was first defined as the pure element, as the exact date of discovery of most elements cannot be accurately determined. There are plans to synthesize more elements, and it is not known how many elements are possible.
In a mixture of gases, each constituent gas has a partial pressure which is the notional pressure of that constituent gas as if it alone occupied the entire volume of the original mixture at the same temperature. The total pressure of an ideal gas mixture is the sum of the partial pressures of the gases in the mixture.
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
Nikolay Dmitriyevich Zelinsky was a Russian and Soviet chemist. Academician of the Academy of Sciences of the Soviet Union (1929).
Azines are a functional class of organic compounds with the connectivity RR'C=N-N=CRR'. These compounds are the product of the condensation of hydrazine with ketones and aldehydes, although in practice they are often made by alternative routes. Ketazines are azines derived from ketones. For example, acetone azine is the simplest ketazine. Aldazines are azines derived from aldehydes.
1,3,5-Triazido-2,4,6-trinitrobenzene, also known as TATNB (triazidotrinitrobenzene) and TNTAZB (trinitrotriazidobenzene), is an aromatic high explosive composed of a benzene ring with three azido groups (-N3) and three nitro groups (-NO2) alternating around the ring, giving the chemical formula C6(N3)3(NO2)3. Its detonation velocity is 7,350 meters per second, which is comparable to TATB (triaminotrinitrobenzene).
Richard Neil Zare is the Marguerite Blake Wilbur Professor in Natural Science and a Professor of Chemistry at Stanford University. Throughout his career, Zare has made a considerable impact in physical chemistry and analytical chemistry, particularly through the development of laser-induced fluorescence (LIF) and the study of chemical reactions at the molecular and nanoscale level. LIF is an extremely sensitive technique with applications ranging from analytical chemistry and molecular biology to astrophysics. One of its applications was the sequencing of the human genome.
Samarium(III) oxide (Sm2O3) is a chemical compound. Samarium oxide readily forms on the surface of samarium metal under humid conditions or temperatures in excess of 150°C in dry air. Similar to rust on metallic iron, this oxide layer spalls off the surface of the metal, exposing more metal to continue the reaction. The oxide is commonly white to off yellow in color and is often encountered as a highly fine dust like powder.
Alexander Zakharovich Patashinski was a Soviet and Russian physicist. He is a professor for Materials Research Scientist and professor at Northwestern University in Evanston, Illinois.
In organophosphorus chemistry, the Kabachnik–Fields reaction is a three-component organic reaction forming α-aminomethylphosphonates from an amine, a carbonyl compound, and a dialkyl phosphonate, (RO)2P(O)H (that are also called dialkylphosphites). Aminophosphonates are synthetic targets of some importance as phosphorus analogues of α-amino acids (a bioisostere). This multicomponent reaction was independently discovered by Martin Kabachnik and Ellis K. Fields in 1952. The reaction is very similar to the two-component Pudovik reaction, which involves condensation of the phosphite and a preformed imine.
Yuri Tsolakovich Oganessian is a Russian-Armenian nuclear physicist who is best known as a researcher of superheavy chemical elements. He participated with the discovery of several elements of the periodic table. He succeeded Georgy Flyorov as director of the Flerov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research in 1989 and is now its scientific director. The heaviest element known of the periodic table, oganesson, is named after him, only the second time that an element was named after a living person.
Perchloratoborate is an anion of the form [B(ClO4)4]−. It can form partly stable solid salts with heavy alkali metals. They are more stable than nitratoborate salts. K[B(ClO4)4] decomposes at 35 °C, Rb[B(ClO4)4] is stable to 50 °C, and Cs[B(ClO4)4] can exist up to 80 °C.
Tetranitratoborate is an anion composed of boron with four nitrate groups. It has formula [B(NO3)4]−. It can form salts with large cations such as tetramethylammonium nitratoborate, or tetraethylammonium tetranitratoborate. The ion was first discovered by C. R. Guibert and M. D. Marshall in 1966 after failed attempts to make neutral (non-ionic) boron nitrate, B(NO3)3, which has resisted attempts to make it; if it exists, it is unstable above −78 °C.
Titanium perchlorate is a molecular compound of titanium and perchlorate groups with formula Ti(ClO4)4. Anhydrous titanium perchlorate decomposes explosively at 130 °C and melts at 85 °C with a slight decomposition. It can sublime in a vacuum as low as 70 °C, and can form vapour at up to 120°. Titanium perchlorate is quite volatile. It has density 2.35. It decomposes to TiO2, ClO2 and dioxygen O2 Also TiO(ClO4)2 is formed during decomposition.
Zirconium perchlorate is a molecular substance containing zirconium and perchlorate groups with formula Zr(ClO4)4. Zr(ClO4)4 is a volatile crystalline product. It can be formed by reacting zirconium tetrachloride with dry perchloric acid at liquid nitrogen temperatures. Zr(ClO4)4 sublimes slowly in a vacuum at 70°C showing that the molecule is covalently bound rather than being ionic. The reaction also forms some zirconyl perchlorate (or zirconium oxyperchlorate) ZrO(ClO4)2 as even apparently pure perchloric acid is in equilibrium with dichlorine heptoxide, hydronium ions and perchlorate ions. This side product can be minimised by adding more dichlorine heptoxide or doing the reaction as cold as possible.
Titanium butoxide is a metal-organic chemical compound with the formula Ti(OBu)4 (Bu = CH2CH2CH2CH3). It is a colorless odorless liquid, although aged samples are yellowish with a weak alcohol-like odor. It is soluble in many organic solvents. It hydrolyzes to give titanium dioxide, which allows deposition of TiO2 coatings of various shapes and sizes down to the nanoscale.
Krishnaswami Venkataraman FNA, FASc, FNASc, FRSC (1901–1981), popularly known as KV, was an Indian organic chemist and the first Indian director at National Chemical Laboratory and University Department of Chemical Technology, Mumbai (UDCT). He was known for the demonstration of an organic chemical reaction involving 2-acetoxyacetophenones which later came to be known as the Baker–Venkataraman rearrangement and for his contributions in developing NCL into one of the leading research centres in organic chemistry. He was an elected fellow of several science academies which included the Royal Society of Chemistry, Academy of Sciences Leopoldina, USSR Academy of Sciences, Prussian Academy of Sciences, Polish Academy of Sciences, Indian Academy of Sciences, and the Indian National Science Academy. The Government of India awarded him the Padma Bhushan, the third highest Indian civilian award, in 1961.
Lithium tetrahydridogallate is the inorganic compound with formula LiGaH4. It is a white solid similar to but less thermally robust than lithium aluminium hydride.
Olga Konstantinovna Bogdanova was a Soviet chemist, a specialist in organic catalysis.
Gas Dynamics Laboratory (GDL) (Russian: Газодинамическая лаборатория) was the first Soviet research and development laboratory to focus on rocket technology. Its activities were initially devoted to the development of solid propellant rockets, which became the prototypes of missiles in the Katyusha rocket launcher, as well as liquid propellant rockets, which became the prototypes of Soviet rockets and spacecraft. At the end of 1933 it became part of the Reactive Scientific Research Institute (RNII). A number of craters on the far side of the Moon are named after GDL employees.
A log-lin vapor pressure chart of Heptene compared with various liquids
