Question

Why are the molecules of hydrocarbons non-polar?

Answer 1

Hint: The chemical compounds that were formed from the atoms of only carbon and hydrogen were known as hydrocarbons. The molecule can be polar when the atoms in that compound have the difference of electronegativity, whereas in a nonpolar molecule there is a very small or no difference in electronegativity.

Complete Step By Step Answer:
Carbon is an element with atomic number $ 6 $ which is a semimetal or metalloid. It possesses the properties of both metal and non-metal. Carbon has the electronegativity value of $ 2.55 $ . Hydrogen is an element with atomic number $ 1 $ and is a non-metal. It has an electronegativity value of $ 2.2 $ .
These elements combine to form different types of chemical compounds. These chemical compounds were known as hydrocarbons.
When the elements do not have more differences in the values of electronegativity, the molecules become polar. When the elements have more differences in the values of electronegativity, the molecule becomes non-polar.
As the difference between carbon and hydrogen is $ 2.55 - 2.2 = 0.35 $ which is a very small difference. Hydrocarbons become non-polar.
Thus, hydrocarbons are nonpolar due to the less electronegativity difference between the carbon and hydrogen atoms present in hydrocarbons.
Polarity is the movement of electrons or ions, as hydrocarbons are nonpolar, hydrocarbons are inert compared to other functional groups.

Note:
Examples of hydrocarbons are alkanes, alkenes, and alkynes. Out of which alkanes are more non-polar due to the absence of unsaturation. These all compounds do not readily participate in chemical reactions due to their non-polar nature.