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carbon group

n. (context chemistry English) the vertical group of the periodic table containing carbon, silicon, germanium, tin and lead; the elements have a valence of 4, and show the typical gradation from nonmetal to metal

Wikipedia
Carbon group

The carbon group is a periodic table group consisting of carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl).

In modern IUPAC notation, it is called Group 14. In the field of semiconductor physics, it is still universally called Group IV. The group was once also known as the tetrels (from Greek tetra, four), stemming from the Roman numeral IV in the group names, or (not coincidentally) from the fact that these elements have four valence electrons (see below). The group is sometimes also referred to as tetragens because it has four electron in its outermost shell or the valence shell. This group is also called crystallogens because this group forms the most crystal compounds when compared to other elements of the periodic table.