Electronegativity and Bond Polarity The electronegativity difference between two bonded atoms helps characterize a bond as ionic, polar covalent, or nonpolar covalent.
These bond types fall on a spectrum from increasingly ionic to decreasingly polar. Ionic
bonds have an electronegativity difference greater than 2.0. A polar covalent bond is a
bond in which electrons are shared but not shared equally between the atoms. The
electronegativity difference of polar covalent bonds is between 0.4 and 2.0. A nonpolar
covalent bond is a bond in which the electrons are shared equally. Nonpolar covalent
bonds have minimal electronegativity differences (0.4 or less).
SEP Use Math Calculate the electronegativity differences and determine the
polarity for the bonds formed by the following pairs of atoms: K and F atoms
and N and O atoms.
Notebook

answer; i do believe the correct answer is (river); /// good luck

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.