http://www.ck12.org Chapter 27. Glossary
photon
A particle of light.physical change
A change that affects the form of a chemical substance but does not change its chemical composition.physical properties
Those properties that can be observed or measured without changing the composition of the matter. Physical
properties of matter include mass, weight, volume, and density.pi bond
Not connected directly between the two atoms, but above and below them.plum pudding model
J. J. Thomson postulated that the atom was comprised of negatively charged particles in a disperse field of
positive charge (positively charged particles had not yet been discovered). This proposed arrangement was
compared to the arrangement of plums in plum pudding.polarity
Polar molecules contain one or more atoms which possess either a partial positive or a partial negative charge.polyatomic
Charged molecules comprised more than two elements.polymer
Are long-chain materials with useful properties.polyprotic acid
Has two or three available hydrogen to react.polysaccharide
Made up of many monosaccharides.positron
This emission involves the conversion of a proton in the nucleus to a neutron (remaining the in the nucleus)
and an ejected positron (positive electron).precision
Describes how close estimates are to one another.pressure
Applied force per unit area on a surface.primary structure
The amino acid sequence.product-favored equilibrium
At the equilibrium, the concentration of products is large and the concentration of reactants is small.