Answer:
Covalent bonds form when two atoms share valence electrons,
while Van der Waals forces cause an attraction between nonpolar
molecules
Explanation:
A covalent bond is said to be formed when two atoms of the same or different elements share electrons. In an ordinary covalent bond, each bonding atom contributes one valence electron while in a dative covalent bond only one of the bonding atoms provides the shared pair of electrons.
Van Der Waals forces is the major intermolecular interaction between non polar compounds. Van Der Waals forces " are caused by correlations in the fluctuating polarizations of nearby particles"(Wikipedia).
In chemistry, adhesion refers to the tendency of unlike molecules to bond with one another, while cohesion refers to the attractive force between molecules of the same type. Surface tension, which is an essential property of water, illustrates the relationship between adhesion and cohesion.
The client should remove all metal objects (such as piercings, rings, jewelry of any kind) the day of the scan.
Answer:
Air born pathogens are minute creatures responsible for causing a variety of illness. These pathogens may be bacteria, virus or fungi and spread through a variety of mechanism. When an infected person sneeze, respiratory droplets add into air. These infectious droplets when inhaled by a healthy person he become ill.Example is flue virus.
