Pipette A pipette is a graduated glass volumetric apparatus used to deliver a stated quantity of liquid in volumetric analysis by titration. Planck's Constant Planck's constant, h, is the proportionality constant defining the relationship between the energy, E, associated with a photon and the frequency, v, of that photon. When the atoms that are linked by a covalent bond have significantly different electronegativities, the electron is likely to spend a greater time near the atom of higher negativity, giving to an unequal distribution of charge between the atoms. In general, the polar bond is stronger than the covalent bond from which it derives. Pollution Pollution is an undesirable change in the physical, chemical, or biological characteristics of the natural environment, brought about by man's activities.
Pollution can occur in the air or in water.
Air Pollution Water Pollution Polyhydric Alcohol Polyhydric alcohols contain several hydroxyl groups in the molecule and are normally obtained by the reduction of sugars. For example, sorbital is obtained by the reduction of glucose. Polymerization is the process by which many small molecules join together to form large molecules. There are two general methods for preparing polymers, which involves the linking of small molecules together to form long chain molecules. In general, addition polymerisations tend to proceed by a Free Radical Mechanism , while condensation polymerisation tends to proceed by an ionic mechanism.