dipole moment: meaning, definition, pronunciation and examples
C1Technical / Scientific
Quick answer
What does “dipole moment” mean?
A quantitative measure of the separation of positive and negative electrical charges within a system.
Audio
Pronunciation
Definition
Meaning and Definition
A quantitative measure of the separation of positive and negative electrical charges within a system.
In physics and chemistry, a vector quantity describing the polarity of a molecule or a charge distribution, equal to the product of the magnitude of the charges and the distance separating them.
Dialectal Variation
British vs American Usage
Differences
No significant lexical or orthographic differences. Pronunciations differ slightly.
Connotations
Identical technical connotations in both dialects.
Frequency
Equally frequent in scientific discourse in both UK and US English.
Grammar
How to Use “dipole moment” in a Sentence
The molecule *has* a dipole moment.The dipole moment *is calculated* from...The dipole moment *of* water is...A dipole moment *arises from*...The magnitude *of the dipole moment* is...Vocabulary
Collocations
Examples
Examples of “dipole moment” in a Sentence
adjective
British English
- The dipole-moment measurement was crucial.
American English
- The dipole moment calculation is complex.
Usage
Meaning in Context
Business
Extremely rare. Only in highly specialized industries dealing with advanced materials or scientific instrumentation.
Academic
Primary domain. Common in physics, chemistry, materials science, and engineering textbooks, papers, and lectures.
Everyday
Virtually never used.
Technical
Core technical term. Essential for describing molecular polarity, dielectric properties, and electromagnetic interactions.
Vocabulary
Synonyms of “dipole moment”
Neutral
Weak
Vocabulary
Antonyms of “dipole moment”
Watch out
Common Mistakes When Using “dipole moment”
- Using it as a countable noun incorrectly (e.g., 'one dipole moment, two dipole moments' is technically correct but 'dipole moment values' is better).
- Forgetting it is a vector (e.g., saying 'the dipole moment is 1.85' without specifying units or direction).
- Confusing 'dipole moment' with 'polarizability'.
FAQ
Frequently Asked Questions
The SI unit is the debye (D) or the coulomb-meter (C·m). 1 D = 3.33564 × 10^-30 C·m.
Yes. If a molecule is perfectly symmetrical and the charge distribution is even, like in methane (CH4) or carbon tetrachloride (CCl4), the net dipole moment is zero, making it non-polar.
Polarity is the qualitative property of having separated charges. The dipole moment is the quantitative, measurable vector that describes the magnitude and direction of that polarity.
Water's relatively large dipole moment (1.85 D) is responsible for its high dielectric constant, its ability to dissolve ionic compounds, its hydrogen bonding, and many of its unique physical properties essential for life.
A quantitative measure of the separation of positive and negative electrical charges within a system.
Dipole moment is usually technical / scientific in register.
Dipole moment: in British English it is pronounced /ˈdʌɪpəʊl ˈməʊmənt/, and in American English it is pronounced /ˈdaɪpoʊl ˈmoʊmənt/. Tap the audio buttons above to hear it.
Learning
Memory Aids
Mnemonic
Think of a magnet: the dipole moment is like its strength and the line from its south to north pole. For charges, it's the 'pull' between separated + and -.
Conceptual Metaphor
A TUG-OF-WARP VECTOR. The strength and direction of the 'pull' created when positive and negative charges are separated.
Practice
Quiz
What does a dipole moment quantitatively describe?