Plastics - Chemistry Encyclopedia
The term "plastic" can be broadly defined as any inherently formless material that can be molded or modeled under heat and/or pressure. It is derived from the Greek word plastikos, meaning a shaped or molded substance.
Platinum - Chemistry Encyclopedia
Plutonium - Chemistry Encyclopedia
Polonium - Chemistry Encyclopedia
Polyesters - Chemistry Encyclopedia
Polyesters are long chain synthetic polymers that have ester linkages. Polyester materials are used as fibers, plastics, and films; in composites and elastomers; and as coatings.
Polymerase Chain Reaction - Chemistry Encyclopedia
The polymerase chain reaction (PCR) is used to make millions of copies of a section of deoxyribonucleic acid (DNA). Until the 1980s obtaining numerous copies of a section of DNA took one to two weeks and required isolation of the DNA, cloning the DNA into a viral or plasmid vector, growing the cloned DNA using living host cells, usually bacteria, and finally isolating the DNA again.
Polysaccharides - Chemistry Encyclopedia
Polysaccharides are long polymers of monosaccharides and their derivatives. Unlike proteins or nucleic acids, these polymers can be either linear or branched, and they can contain only one type of monosaccharide (homopolysaccharides), or more than one (heteropolysaccharides).
Potassium - Chemistry Encyclopedia
Praseodymium - Chemistry Encyclopedia
Primary Structure - Chemistry Encyclopedia
There are four recognized levels of protein structure: primary, secondary, tertiary, and quaternary. The primary structure refers to the amino acid sequence of a protein.
Promethium - Chemistry Encyclopedia
Protactinium - Chemistry Encyclopedia
Planck, Max - Chemistry Encyclopedia
Polymers, Natural - Chemistry Encyclopedia
The word "polymer" means "many parts" (from the Greek poly, meaning "many," and meros, meaning "parts"). Polymers are giant molecules with molar masses ranging from thousands to millions.
Polymers, Synthetic - Chemistry Encyclopedia
Polymers are large molecules composed of repeated chemical units. The smallest repeating unit is called a mer.
Priestley, Joseph - Chemistry Encyclopedia
Joseph Priestley was a dissenting Unitarian minister in England at a time when adherence to the established Church of England was of great importance. Preaching was a difficult career for Priestley—because his Unitarian views were unpopular and because he spoke with a stammer.