Subscript Three

A text app’s symbol menu or your system’s character map can insert it.

This standalone character works in plain-text fields that strip rich formatting. In a document or equation editor you control, use subscript formatting or MathML for a full expression.

The font must contain a glyph for it. If it does not, a browser may show a box or another fallback; the missing glyph does not change the character’s meaning.

What does ₃ mean in a chemical formula?

It counts atoms of the element or group just before it.

In NH₃, it means three hydrogen atoms for each nitrogen atom. In mathematics, x₃ can label the third member of a sequence or family, if that is how the notation defines it.

Should I use ₃ or HTML subscript formatting?

Use the character in plain text; use markup for structured text.

HTML’s element changes how text is displayed, while MathML, a markup language for mathematics, can express mathematical structure. Unicode guidance treats encoded subscript digits as useful for preserving older text or specialized notation; markup is the better fit for general styling.

This matters when another tool searches or processes text: ₃ is one character, whereas markup can apply subscript styling to a longer expression.