The Bohr model of a silicon atom includes notations for 14 protons and 14 neutrons in the nucleus plus designations for three concentric circles for electrons. The inner circle contains two electrons, the middle circles have eight electrons and there are four valence electrons on the outer circle. Electrons appear as small dots on the Bohr model.
Valence electrons, or electrons involved in bonds with other atoms and molecules, are on the outer edge of the Bohr model. In Louisiana Tech's illustration, the valence electrons are in red to differentiate them from other electrons. The outer shell of electrons allows silicon to have unique electrical properties.
Silicon is widely used in the electronics industry for microchips, solar panels and transistors. Liquid silicon is an ingredient for sealants, paint and adhesives. Traditional glass is made by melting and reforming silicon. The element makes up 25.7 percent of the Earth's crust, the second-most abundant element by weight after oxygen.
A Bohr model is an approximation of an atom's structure. The design was proposed by Niels Bohr in 1915 in an attempt to illustrate how atoms work. Although fundamentally correct, electrons more rightly form a cloud around the nucleus of an atom because the subatomic particles revolve around the nucleus at incredibly high speeds. A Bohr model attempts to quantify electrons in their orbits.