Non-polar

In chemistry and physics, 'non-polar' describes a molecule or chemical bond in which electrons are shared equally between atoms. This even distribution results in the absence of a significant charge separation or dipole moment, meaning one end of the molecule does not have a slightly positive or negative charge compared to the other. non-polar molecules tend to be hydrophobic (water-repelling) and are soluble in other non-polar solvents but not in polar solvents like water. This characteristic arises from the weak intermolecular forces, primarily London dispersion forces, that hold non-polar molecules together. The symmetrical arrangement of atoms and electron distribution are key to non-polarity.

Non-polar meaning with examples

• 1. Consider methane (CH₄). The carbon-hydrogen bonds are relatively non-polar because carbon and hydrogen have similar electronegativities. Due to its tetrahedral shape, the molecule exhibits no net dipole moment, making it non-polar overall. As a result, methane is insoluble in water and is primarily held together by weak van der Waals forces. This property is crucial in the behavior of natural gas.
• 2. Fats and oils are composed largely of long hydrocarbon chains which are mostly non-polar due to their carbon-hydrogen bonds. This explains why they are hydrophobic, allowing them to form membranes. This non-polarity enables the efficient storage of energy, a critical function for the survival of many organisms and allows for the easy diffusion through hydrophobic cell membranes.
• 3. The molecules of benzene (C₆H₆) are non-polar due to the symmetrical structure with equal sharing of electrons within the carbon ring. This lack of polarity results in benzene's low solubility in water and its ability to dissolve other non-polar substances. The stability and non-polarity of the benzene ring make it a versatile building block in organic chemistry.
• 4. When a molecule of hydrogen gas (H₂) forms a bond, the two identical hydrogen atoms share electrons equally, resulting in a non-polar bond. This even electron distribution results in no net charge separation, making the hydrogen molecule non-polar. The non-polarity determines that there are weak intermolecular forces, and it remains a gas at relatively low temperatures.