Search results
Results from the WOW.Com Content Network
Mercury is a chemical element; it has symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum (/ h aɪ ˈ d r ɑːr dʒ ər ə m / hy-DRAR-jər-əm) from the Greek words hydor ' water ' and argyros ' silver ', from which its chemical symbol is derived. [9]
This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.
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 ...
Each distinct atomic number therefore corresponds to a class of atom: these classes are called the chemical elements. [5] The chemical elements are what the periodic table classifies and organizes. Hydrogen is the element with atomic number 1; helium, atomic number 2; lithium, atomic number 3; and so on.
There are seven stable isotopes of mercury (80 Hg) with 202 Hg being the most abundant (29.86%). The longest-lived radioisotopes are 194 Hg with a half-life of 444 years, and 203 Hg with a half-life of 46.612 days. Most of the remaining 40 radioisotopes have half-lives that are less than a day.
The mass number is different for each isotope of a given chemical element, and the difference between the mass number and the atomic number Z gives the number of neutrons (N) in the nucleus: N = A − Z. [2] The mass number is written either after the element name or as a superscript to the left of an element's symbol.
Discover the best free online games at AOL.com - Play board, card, casino, puzzle and many more online games while chatting with others in real-time.
The chemists used an "atomic mass unit" (amu) scale such that the natural mixture of oxygen isotopes had an atomic mass 16, while the physicists assigned the same number 16 to only the atomic mass of the most common oxygen isotope (16 O, containing eight protons and eight neutrons).