picometre
Học thuậtThân thiện
Definition
- Noun:
- A unit of length in the metric system: A picometre is a unit of measurement for length or distance. It is equal to one trillionth (1/1,000,000,000,000) of a metre.
Usage
- The picometre is used in scientific fields, particularly in physics and chemistry, to measure extremely small distances, such as the sizes of atoms and the wavelengths of certain types of radiation.
- It is often abbreviated as pm.
Examples
- Noun:
- The radius of a hydrogen atom is about 25 picometres.
- X-rays have wavelengths on the order of picometres.
Advanced Usage
- Scientific Notation: In scientific contexts, a picometre is expressed as 1 × 10⁻¹² metres.
- Comparison: To visualize its scale, a picometre is to a metre what a metre is to the distance from the Earth to the Sun.
Variants and Related Words
- Picometer: The American English spelling of "picometre".
- Picometric (adj): Relating to or measured in picometres. (e.g., ).
Synonyms
- There are no direct synonyms for this specific unit of measurement. It can be described as a trillionth of a metre.
Related Phrases
- While not a phrasal verb, the term is commonly part of compound units like picometre-scale (adj), describing objects or phenomena measured in picometres.
Noun
- a metric unit of length equal to one trillionth of a meter