The main group elements
Within the p-block at the boundary between the metallic elements (grey elements) and nonmetal elements (green elements) there is positioned boron and silicon that are metalloid in character (pink elements), i.e., they have low electrical conductivity that increases with temperature.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"Andrew Barron, Periodic Trends for the Main Group Elements. October 27, 2013."
http://cnx.org/content/m31489/latest/#id5055553
OpenStax CNX
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