Placer County (/ËplaesÉr/ ËPLÃ¦SÉR-plas), Ér officially The county Of, placer is a county located in The.U. s state Of. California as of the 2010, census the population 348,432. 348432 the county seat Is. Auburn Placer county is included in The-Sacramento-Roseville-Arden, ARCADE Ca Metropolitan Statistical. area
A crystal or crystalline solid is a solid material whose constituents, such as atoms, molecules or ions, are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. crystal is a solid where the atoms form a periodic arrangement. (Quasicrystals are an exception, see below .). Not all solids are crystals. For example, when liquid water starts freezing, the phase change begins with small ice crystals that grow until they fuse, forming a polycrystalline structure.
Liquid crystal. Liquid crystals (LCs) are matter in a state which has properties between those of conventional liquids and those of solid crystals. For instance, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. There are many different types of liquid-crystal phases, which can be distinguished by their different optical properties (such as birefringence).