1 bacteria can neutralize the antibiotic before it has an effect. 2  bacteria may be able to pump the antibiotic out. 3  bacteria may be able to change the site (receptor) where the antibiotic normally works.  bacteria can mutate and transfer genetic material that codes for resistance to other bacteria.
A covalent bond forming H 2 (right) where two hydrogen atoms share the two electrons. A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. double bond between two given atoms consists of one sigma and one pi bond, and a triple bond is one sigma and two pi bonds. Covalent bonds are also affected by the electronegativity of the connected atoms which determines the chemical polarity of the bond.
Polar covalent bonding. In most covalent compounds [compound: A compound is a substance formed by the chemical union (involving bond formation) of two or more elements.] the bonding is polar covalent. Covalent bonds with unequal electron sharing are called polar covalent bonds.hen two atoms bonded by a covalent bond have the same electronegativity the electrons will be equally shared. This is called pure (non-polar) covalent bonding. For example, the chlorine molecule, Cl 2.