Search results
Results from the WOW.Com Content Network
Valence shell electron pair repulsion (VSEPR) theory (/ ˈ v ɛ s p ər, v ə ˈ s ɛ p ər / VESP-ər, [1]: 410 və-SEP-ər [2]) is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms. [3]
In three-dimensional space, its most symmetric form is generated from six line segments parallel to the face diagonals of a cube. [2] It tiles space to form the bitruncated cubic honeycomb . Any zonohedron whose faces have the same combinatorial structure as one of these five shapes is a parallelohedron, regardless of its particular angles or ...
Major types of shapes that either constitute or define a volume. Figure Definitions Images Parallelepiped: A polyhedron with six faces , each of which is a parallelogram; A hexahedron with three pairs of parallel faces; A prism of which the base is a parallelogram; Rhombohedron: A parallelepiped where all edges are the same length
According to the VSEPR theory of molecular geometry in chemistry, which is based on the general principle of maximizing the distances between points, a square antiprism is the favoured geometry when eight pairs of electrons surround a central atom. One molecule with this geometry is the octafluoroxenate(VI) ion (XeF 2−
It follows that all vertices are congruent, and the polyhedron has a high degree of reflectional and rotational symmetry. Uniform polyhedra can be divided between convex forms with convex regular polygon faces and star forms. Star forms have either regular star polygon faces or vertex figures or both. This list includes these:
In geometry, a zonohedron is a convex polyhedron that is centrally symmetric, every face of which is a polygon that is centrally symmetric (a zonogon).Any zonohedron may equivalently be described as the Minkowski sum of a set of line segments in three-dimensional space, or as a three-dimensional projection of a hypercube.
a hexahedron with three pairs of parallel faces, a polyhedron with six faces , each of which is a parallelogram, and; a prism of which the base is a parallelogram. The rectangular cuboid (six rectangular faces), cube (six square faces), and the rhombohedron (six rhombus faces) are all special cases of parallelepiped.
A regular polyhedron is highly symmetrical, being all of edge-transitive, vertex-transitive and face-transitive. In classical contexts, many different equivalent definitions are used; a common one is that the faces are congruent regular polygons which are assembled in the same way around each vertex .