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 ...
Withering away of the state is a Marxist concept coined by Friedrich Engels referring to the idea that, with the realization of socialism, the state will eventually become obsolete and cease to exist as society will be able to govern itself without the state and its coercive enforcement of the law.
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 ...
41 of the 118 known elements have names associated with, or specifically named for, places around the world or among astronomical objects. 32 of these have names tied to the places on Earth, and the other nine are named after to Solar System objects: helium for the Sun; tellurium for the Earth; selenium for the Moon; mercury (indirectly), uranium, neptunium and plutonium after their respective ...
A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus.
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).
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 ...
[10] [13] Different meanings may be attached to the term, depending on the context. For example, a heavy metal may be defined on the basis of density, [14] the distinguishing criterion might be atomic number, [15] or the chemical behaviour. [16] Density criteria range from above 3.5 g/cm 3 to above 7 g/cm 3. [17]