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Boron is a special case, being the only nonmetal in group 13. The alkali metal borides tend to be boron-rich, involving appreciable boron–boron bonding involving deltahedral structures, [10]: 147–8 and are thermally unstable due to the alkali metals having a very high vapour pressure at elevated temperatures. This makes direct synthesis ...
Usually includes Ag, Au, and the platinum-group metals. Non-ferrous metals - Metals or alloys that do not contain iron in appreciable amounts. Platinum group – Ru, Rh, Pd, Os, Ir, Pt. Post-transition metals – The metals coming after the transition metals. Many other names have been used for this set, and its borders are not agreed on.
Groups may also be identified using their topmost element, or have a specific name. For example, group 16 is also described as the "oxygen group" and as the " chalcogens ". An exception is the " iron group ", which usually refers to group 8 , but in chemistry may also mean iron , cobalt , and nickel , or some other set of elements with similar ...
a Group 1 is composed of hydrogen (H) and the alkali metals. Elements of the group have one s-electron in the outer electron shell. Hydrogen is not considered to be an alkali metal as it is not a metal, though it is more analogous to them than any other group. This makes the group somewhat exceptional.
118 chemical elements have been identified and named officially by IUPAC.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).
a Group 1 is composed of hydrogen (H) and the alkali metals. Elements of the group have one s-electron in the outer electron shell. Hydrogen is not considered to be an alkali metal as it is not a metal, though it is more analogous to them than any other group. This makes the group somewhat exceptional.
Sodium (Na) is an alkali metal. It is present in Earth's oceans in large quantities in the form of sodium chloride (table salt). Magnesium (Mg) is an alkaline earth metal. Magnesium ions are found in chlorophyll. Aluminium (Al) is a post-transition metal. It is the most abundant metal in the Earth's crust. Silicon (Si) is a metalloid.
It is not advisable to use the earlier group-naming systems, because they are ambiguous: "group VIA" meant the oxygen group some systems, but meant the chromium group in others. alkali metal = group 1 but without hydrogen (alkali is not strictly a group name then) alkaline earth metal = group 2; pnictogen = group 15; chalcogen = group 16 ...