Cobalt for "goblin ore") for some of the blue-pigment producing minerals; they were so named because they were poor in known metals, and gave poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the "kobold". Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as for example cobaltite (CoAsS). The element is however more usually produced as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo
Chemical element hydrogen and deuterium). Thus, all carbon isotopes have nearly identical chemical properties because they all have six protons and six electrons, even though carbon atoms may, for example, have 6 or 8 neutrons. That is why the atomic number, rather than mass number or atomic weight, is considered the identifying characteristic of a chemical element. The symbol for atomic number is "Z". Isotopes are atoms of the same element (that is, with the same number of protons in their atomic nucleus), but having "different" numbers of neutrons. Thus, for example, there are three main isotopes of carbon. All carbon atoms