The annual production of gold in the world is 2500 tons per year. The other countries where gold is being mined include USA, Canada and Russia. The biggest producer of gold is China from around two third of the gold (around 455 tons) in world is produced. The term “electrum” is used for gold ore that have silver content of more than 20%. Naturally, most of the gold present in the Earth’s crust is in combination with silver. Gold is found in association of pyrites deposits and from quarts and gravels. Gold also exists in the form of alloy, such as amalgam (with mercury) or with silver. It is also present in river beds as rock bound gold is released by erosion of rock by running water. Gold is widely present in the Earth’s crust (0.3 ppm by weight). The symbol of gold comes from a word of Latin origin, aurum, which is originated from Aurora, which is the goddess of morning glow. Geolo (Sanskrit origin meaning to shine) means yellow. The word gold has been originated from the word “geolo” used by Anglo-Saxon civilization that inhabited England in the 5 th century. Gold has been considered as perfect and precious metal since ancient times, and long relentless but in vain efforts have been made over centuries to transform various metals into gold, a concept known as alchemy. Gold coins were made in the reign of King Croesus of Lydia (modern Turkey) (561-547 BC). Pure gold has been found from around 6000 years ago Israel kingdom. have been found to contain gold from civilization of 3800 to 2000 BC. And gold made items, such as masks, graves etc. The Egyptians in around 2000 BC started mining of gold. Gold is the metal of prehistoric times and it was collected from water streams in form of particles. It is unreactive and is highly resistant to corrosion which makes it favorable for wide range of medicinal, ornamental and structural use. This fact has key implications for the building up of the periodic table of elements.Gold is a precious metal which has been in human use since 2000 BC. The ordering of the electrons in the ground state of multielectron atoms, starts with the lowest energy state (ground state) and moves progressively from there up the energy scale until each of the atom’s electrons has been assigned a unique set of quantum numbers. It is the Pauli exclusion principle that requires the electrons in an atom to occupy different energy levels instead of them all condensing in the ground state. In the periodic table, the elements are listed in order of increasing atomic number Z. The number of electrons in each element’s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. The configuration of these electrons follows from the principles of quantum mechanics. The chemical properties of the atom are determined by the number of protons, in fact, by number and arrangement of electrons. See also: Atomic Number – Does it conserve in a nuclear reaction? Atomic Number and Chemical PropertiesĮvery solid, liquid, gas, and plasma is composed of neutral or ionized atoms. It is the electrons that are responsible for the chemical bavavior of atoms, and which identify the various chemical elements. In a neutral atom there are as many electrons as protons moving about nucleus. The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10 -19 coulombs. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z. The nucleus is composed of protons and neutrons. The atom consist of a small but massive nucleus surrounded by a cloud of rapidly moving electrons.
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