Is selenium a metalloid?
Selenium is a metalloid (an element intermediate in properties between the metals and the nonmetals). The gray, metallic form of the element is the most stable under ordinary conditions; this form has the unusual property of greatly increasing in electrical conductivity when exposed to light.
What are the isotopes of the first 20 elements?
Isotopes (Stable) of the elements
|Neon||20Ne, 21Ne, 22Ne|
|Magnesium||24Mg, 25Mg, 26Mg|
What is an isotope on the periodic table?
Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element’s atomic number on the Periodic Table. For example, carbon has six protons and is atomic number 6.
Which element has most isotopes?
Isotopes can be stable or unstable, and they decay by emitting radiation. The element with the largest number of stable isotopes is tin (symbol Sn and atomic number 50) with 10 isotopes. Tin was first extracted and used in the Bronze Age (circa 3000 BC).
What is another name for selenium?
Selenium exists in two forms: inorganic (selenate and selenite) and organic (selenomethionine and selenocysteine) .
What are metalloids give 2 examples?
Boron, silicon, germanium, arsenic, antimony, and tellurium are commonly recognised as metalloids.
Why is carbon-12 an isotope?
Isotopes are forms of the same element with equal numbers of protons but different numbers of neutrons. For example, both carbon-12 and carbon-14 have 6 protons. But carbon-12 has 6 neutrons while carbon-14 has 8 neutrons. By definition, carbon-12, carbon-13 and carbon-14 are all isotopes of the carbon.
Who invented Isobar?
Alfred Walter Stewart
While the nuclei of these nuclides all contain 40 nucleons, they contain varying numbers of protons and neutrons. The term “isobars” (originally “isobares”) for nuclides was suggested by Alfred Walter Stewart in 1918. It is derived from the Greek word isos, meaning “equal” and baros, meaning “weight”.