nonpolar
Học thuậtThân thiện
Definition
Adjective: 1. Not having distinct or opposite poles; not ionic: Describes a molecule or substance that does not have a separation of electric charge, meaning it lacks positive and negative poles. This typically occurs due to an even distribution of electrons within covalent bonds. 2. Lacking polarity; not forming ions in solution: Refers to substances that do not dissociate into charged particles (ions) when dissolved.
Usage and Examples
- Describing molecular structure:
- Water is a polar molecule, whereas oil is a nonpolar substance.
- The nonpolar covalent bond means the electrons are shared equally between the atoms.
- Describing solubility and behavior:
- Nonpolar solvents are often used to dissolve oils and fats.
- This compound is nonpolar and will not mix with water.
Advanced Usage and Scientific Context
- In chemistry, nonpolar is a fundamental concept contrasting with . It explains the "like dissolves like" rule, where nonpolar solutes dissolve best in nonpolar solvents.
- In biology, nonpolar amino acids are often found in the interior of proteins, away from the aqueous environment.
- The term can describe entire molecules (e.g., methane, CH₄) or specific bonds within a molecule (e.g., the C-H bond).
Variants and Related Words
- Nonpolarity (noun): The state or quality of being nonpolar.
- The nonpolarity of the lipid bilayer is crucial for cell membrane function.
- Nonionic (adjective): A closely related term often used interchangeably with nonpolar in some contexts, especially regarding surfactants or substances that do not form ions. (As referenced: "a nonionic substance").
- A nonionic detergent is gentler on fabrics.
Synonyms
- Apolar: A direct synonym, especially used in scientific literature.
- Hydrophobic: While not a perfect synonym, hydrophobic ("water-fearing") substances are typically nonpolar.
- Nonionic: Specifically referring to the lack of ions.
Antonyms
- Polar: Having distinct positive and negative poles.
- Ionic: Relating to, composed of, or using ions.
- Hydrophilic: ("Water-loving"); typically polar.
Adjective
- not ionic
- a nonionic substance