A parasitic infectious microbe, composed almost entirely of protein and nucleic acids, which can cause disease(s) in humans. Viruses can reproduce only within living cells. They […]
A tube with a narrow throat (a constriction) that increases the velocity and decreases the pressure of the liquid passing through it, creating a partial vacuum […]
A whole number (positive or negative) representing the power of one element to combine with another. In general terms, the valence number represents the number of […]
A mechanical device which automatically vents a water line to the atmosphere when subjected to a partial vacuum, thus preventing back-flow. (See back-flow, air gap, back-flow […]