chemical formula
Học thuậtThân thiện
Definition
Noun: A symbolic representation of the composition of a chemical compound. It uses atomic symbols and numerical subscripts to show the types and numbers of atoms present in a single molecule or formula unit of the substance.
Usage
A chemical formula is written to precisely define the elemental makeup of a pure substance. It is a fundamental notation in chemistry.
Examples
- The chemical formula for water is H₂O.
- Sodium chloride has the chemical formula NaCl.
- You can determine the molar mass from the chemical formula.
Advanced Usage
- Empirical Formula: A type of chemical formula that shows the simplest whole-number ratio of atoms in a compound. For example, the empirical formula for benzene is CH, while its molecular formula is C₆H₆.
- Molecular Formula: A type of chemical formula that indicates the exact number of each type of atom in a molecule. Glucose has the molecular formula C₆H₁₂O₆.
- Structural Formula: A representation that shows not only the number and type of atoms but also the arrangement of atoms and the bonds between them.
Variants and Related Words
- Formula (n): In a scientific context, this is often used as a shorter form of "chemical formula." It can also mean a general mathematical or scientific rule expressed in symbols.
- Empirical Formula (n): The simplest formula.
- Molecular Formula (n): The exact formula for a molecule.
- Structural Formula (n): A formula showing atom connectivity.
Synonyms
- Molecular Formula (when referring specifically to that type).
- Composition Notation.
Notes on Different Meanings
The word formula alone has broader meanings outside of chemistry, such as a method or procedure for achieving something (e.g., a formula for success), or a mathematical relationship. The term chemical formula is specific to chemistry.
Noun
- a representation of a substance using symbols for its constituent elements