Question

what is non polar covalent bond in chemistry

Answer 1

Non polar covalent bond occurs when two atoms share a pair of electrons with each other. 

Answer 2

Non polar covalent bonds are a type of chemical bond where two atoms share equal electrons with each other.
example: bond between hydrogen atoms because they equally share the electrons.
Another example is bond between chlorine atoms.
Note: Non polar covalent bonds are very strong bonds requiring a large amount of energy to break the bond.