Methane molecule is non-polar molecule. Explain.

The bond formed between dissimilar atoms can be non-polar if their electronegativity difference is little and their structure permits the shared pair of electrons to attract equally the linked atoms and thus the molecule becomes symmetrical.
The shared electron pairs in Methane are at an equal distance from the Carbon and the Hydrogen atoms because the two have nearly equal electronegativities (carbon = 2.5, hydrogen = 2.1).