Gold gets its name from the Anglo-Saxon word "geolo" for yellow. It has long been a substance of value and wealth. Civilizations such as Ancient Egypt used gold over 5000 years ago. Gold has been known about since ancient times. Other applications for gold include heat shielding, dental work, cancer treatment, and decoration such as gold thread and gold plating. Many electrical contacts and connectors are plated with gold for protection and reliability. Gold is used a lot in the electronics industry because of its good electrical conductivity and resistance to corrosion. Generally gold is alloyed with other metals such as copper or silver in order to make it harder and more durable. Pure gold is called 24 karat gold and it is very soft. When gold is used as jewelry or for coins, it is generally not pure gold. Gold is also considered an important and reliable investment. Today it is still used for jewelry and for some collector's edition coins. Gold has been used for thousands of years to make jewelry and coins. However, the process for retrieving gold from ocean water costs more than the gold itself. It can be found in veins underground or in small fragments in sandy riverbeds. Because it doesn't react with very many other elements, it is often found in its native form in the Earth's crust or mixed with other metals like silver. Gold is an extremely rare element on Earth. It is also one of the most resistant metals to corrosion and rust when exposed to air and water. It is an excellent conductor of electricity and heat. Gold is more than just a beautiful metal. It is also one of the most ductile metals and can be easily stretched into a long wire. Gold is the most malleable of the metals meaning that it can be pounded into a very thin sheet. It is very dense and heavy, but also fairly soft. Under standard conditions gold is a shiny yellow metal. Gold atoms have 79 electrons and 79 protons with 118 neutrons in the most abundant isotope. Gold is the third element in the eleventh column of the periodic table. Discovered by: Known about since ancient times.Geological specimens are known in which the element has an isotopic composition outside the limits for normal material.See table 1 for details of range and original paper for the atomic weight of the element from different sources.However three such elements (Th, Pa, and U) do have a characteristic terrestrial isotopic composition, and for these an atomic weight is tabulated. , indicates the mass number of the longest-lived isotope of the element.
Substantial deviations in atomic weight of the element from that given in the Table can occur. Modified isotopic compositions may be found in commercially available material because it has been subject to an undisclosed or inadvertant isotopic fractionation.Value being given the tabulated value should be applicable to any normal material. Range in isotopic composition of normal terrestrial material prevents a more precise.The difference between the atomic weight of the element in such specimens and that given in the Table may exceed the stated uncertainty. See original paper for the range of these elements from different sources List of Elements with Range of Atomic Weights. See also a copy of the periodic table with atomic weights to five significant figures. See below for the elements listed in Atomic Number Order or Name order.
#Au periodic table full#
The original paper should be consulted for full details of the variation in atomic weight and the half life of the radioisotopes quoted below.Ī number in parentheses indicates the uncertainty in the last digit of the atomic weight. For radioactive elements the isotope with the longest half-life is quoted in parenthesis. In the other lists the values quoted are those suggested for material where the origin of the sample is unknown. The standard atomic weights of twelve elements having two or more stable isotopes have variability of atomic-weight values in natural terrestrial materials. Previous values may be consulted from the 1993 table, the 1995 table, the 1997 table, the 1999 table, the 2001 table, the 2005 table, the 2007 table, the 2009 table, the 2011 table, the 2013 table, the 2015 table or the 2019 table. World Wide Web version of atomic weight data originally prepared by G. These tables are based on the 2021 table with changes from the 2019 table for the values of Ar, Hf, Ir, Pb and Yb and changes to the uncertainty for Al, Au, Co, F, Ho, Mn, Nb, Pa, Pr, Rh, Sc, Tb, Tm, and Y. 2021 Atomic Weights IUPAC Commission on Isotopic Abundances and Atomic Weights.
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