Meaning & use
subscript
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Meanings
nouncountablechemistry
A small number written below and to the right of a chemical symbol to show how many atoms of that element are in a formula unit.
Grammar: Countable in formulas and discussions: a subscript of 2, the subscripts in H₂O.
Patterns
- chemical subscript
- subscript shows atoms
- subscript in a formula
In H₂O, the subscript 2 means two hydrogen atoms.
A coefficient multiplies the whole formula, but a subscript changes the atom count.
Students must not move a subscript when balancing an equation.
nouncountablemathematicscomputing
A character printed or written slightly lower than the main line in mathematics, computing, or general typography.
Grammar: Countable and also used attributively before noun: subscript notation, a subscript index.
Patterns
- subscript notation
- subscript index
- use a subscript
The variable x₁ uses a subscript to label the first value.
In the spreadsheet, the subscript format made the footnote tiny.
Some programming styles reserve a leading subscript for metadata.
Word forms
| plural | subscripts |
|---|
Common combinations
- chemical subscript
- A chemical subscript tells how many atoms are bonded in the formula.
- subscript notation
- Subscript notation keeps the labels of several variables clear.
- change the subscript
- Do not change the subscript of a polyatomic ion when balancing the equation.
Synonyms and how they differ
- index
- Index can mean an identifying label or position; subscript specifically sits below the line.
Opposites
Word family
- subscripted adjective
- Written with a subscript character or index.
Commonly confused: subscript or superscript? subscript or coefficient?
subscript vs superscript
A subscript sits below the line and counts atoms; a superscript sits above the line and often shows charge or powers.
subscript vs coefficient
A coefficient is a number before a formula; a subscript is inside the formula after an element symbol.
Practice
In the formula CO₂, what does the subscript 2 tell you?
Choose one answer.
The subscript after O gives the number of oxygen atoms in one molecule. A charge would be a superscript, and a coefficient would stand before the whole formula.
Make it your own
Write a sentence using “subscript”, then check it and compare it with the examples above.