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Californium is a synthetic chemical element; it has symbol Cf and atomic number 98. It was first synthesized in 1950 at Lawrence Berkeley National Laboratory [11] (then the University of California Radiation Laboratory) by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be ...
e. This list of chemical elements named after places includes elements named both directly and indirectly for places. 41 of the 118 chemical 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 Earth and the other 10 have names connected to ...
Two examples are kamacite and taenite, which are found in iron meteorites; these species differ by the amount of Ni in the alloy; kamacite has less than 5–7% nickel and is a variety of native iron, whereas the nickel content of taenite ranges from 7–37%. Arsenic group minerals consist of semi-metals, which have only some metallic traits ...
t. e. The architecture of the California missions was influenced by several factors, those being the limitations in the construction materials that were on hand, an overall lack of skilled labor, and a desire on the part of the founding priests to emulate notable structures in their Spanish homeland. While no two mission complexes are identical ...
Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and ...
Found on Earth in trace quantities by Olavi Erämetsä in 1965; so far, promethium is the most recent element to have been found on Earth. [189] 97 Berkelium: 1949 G. Thompson, A. Ghiorso and G. T. Seaborg (University of California, Berkeley) Created by bombardment of americium with alpha particles. [190] 98 Californium: 1950 S. G. Thompson, K ...
List of chemical elements. 118 chemical elements have been identified and named officially by IUPAC. 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]
Placer mining (ˈplæsər) [ 1 ] is the mining of stream bed deposits for minerals. [ 2 ] This may be done by open-pit mining or by various surface excavating equipment or tunneling equipment. Placer mining is frequently used for precious metal deposits (particularly gold) and gemstones, both of which are often found in alluvial deposits ...