Search results
Results from the WOW.Com Content Network
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
unknown phase 105 Db Dubnium: Dubna, Russia, where it was discovered in JINR: 5 7 d-block [268] (21.6) – – – – – synthetic unknown phase 106 Sg Seaborgium: Glenn Seaborg, American chemist 6 7 d-block [267] (23–24) – – – – – synthetic unknown phase 107 Bh Bohrium: Niels Bohr, Danish physicist 7 7 d-block [270] (26–27 ...
Pages in category "Lists of chemical elements" The following 12 pages are in this category, out of 12 total. This list may not reflect recent changes. ...
Lavoisier writes the first modern list of chemical elements – containing 33 elements including light and heat but omitting Na, K (he was unsure of whether soda and potash without carbonic acid, i.e. Na 2 O and K 2 O, are simple substances or compounds like NH 3), [91] Sr, Te; some elements were listed in the table as unextracted "radicals ...
The Incompleat Chymist: Being an Essay on the Eighteenth-Century Chemist in His Laboratory, with a Dictionary of Obsolete Chemical Terms of the Period (Smithsonian Studies in History and Technology, Number 33). Smithsonian Institution Press. Giunta, Carmen. Glossary of Archaic Chemical Terms: Introduction and Part I (A-B). Classic Chemistry.
Chemical formulas can be used to describe the relative amounts of elements present in a compound. For example, the chemical formula for water is H 2 O: this means that each molecule of water is constituted by 2 atoms of hydrogen (H) and 1 atom of oxygen (O). The chemical composition of water may be interpreted as a 2:1 ratio of hydrogen atoms ...
Atoms of one element can be transformed into atoms of a different element in nuclear reactions, which change an atom's atomic number. Historically, the term "chemical element" meant a substance that cannot be broken down into constituent substances by chemical reactions, and for most practical purposes this definition still has validity.