Use electronegativity to explain why some molecules are attracted to a charged wand

Electronegativity refers to the ability or chemical property of an atom to attract (bonding electrons within the molecule) towards itself. Because of this property, partial charges (slightly positive or slightly negative charge) can occur in molecules with atoms that have differences (i.e. relatively large) in their electronegativities.

These molecules with partial charges distributed within them are called "polar" molecules. Because of their partial charges, they are attracted to the charged wand. 

It is known that in charge interactions, those with opposite charges attract. Thus, if the charged wand has a positive charge, the slightly negative charge of the polar molecules will be attracted to the wand. If the wand has a negative charge, the slightly positive charge of the polar molecules will be attracted to the wand. 

Nonpolar molecules, which are molecules without uneven charge distributions within them, do not have slightly positive and negative parts. Thus, they will not be attracted to a charged wand.