Common colds are caused by viruses and antibiotics only work in bacteria. Antibiotics work by targeting the different replication processes and functional characteristics of bacteria. Virus on the other hand are only active once they have invaded something to use as a host. Therefore it is more difficult to target the mechanisms of viruses because they are usually dormant and have different organelles than of bacteria.
By using exponents, we can reformat numbers. This can be helpful, in much the same way that it's helpful (that is, it's easier) to write "twelve trillion" rather than 12,000,000,000,000., or "thirty nanometers" rather than "0.00000003<span> meters</span>
If atoms share two , three or more pairs of electrons..they are covalent bonds..for example, methane
if the atoms share only a lone pair of electron contributed by only one of the combining atoms but shared by both ..then it is a coordinate bond ..for example, ammonium ion
