Silver the periodic table) is useful in nuclear reactors because of its high thermal neutron capture cross-section, good conduction of heat, mechanical stability, and resistance to corrosion in hot water. The word "silver" appears in Anglo-Saxon in various spellings, such as "seolfor" and "siolfor". A similar form is seen throughout the Germanic languages (compare Old High German "silabar" and "silbir"). The chemical symbol Ag is from the Latin word for "silver", "argentum" (compare Ancient Greek ἄργυρος, "árgyros"), from the Proto-Indo-European root *"h₂erǵ-" (formerly reconstructed as "*arǵ-"), meaning "white" or "shining": this was the usual Proto-Indo-European word for the metal, whose reflexes
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