Chemistry Symbols: How to Type H₂O, Ion Charges and Reaction Arrows
Quick answer: in Word and Google Docs, type the formula normally and format the numbers: subscript with Ctrl+= in Word or Ctrl+, in Docs, superscript with Ctrl+Shift+= or Ctrl+.. For plain text (chats, social media, file names), use the subscript and superscript characters such as ₂ and ⁺ from the table above. The reaction arrow → is Alt+26; the equilibrium arrow ⇌ has no Alt code (Word: 21CC then Alt+X).
Quick reference: every method
Every Alt code below is verified against the real Windows code pages — where none exists we say so, rather than list one that won’t work.
| Char | Name | Windows | Mac | HTML | Word (Alt+X) | Unicode |
|---|---|---|---|---|---|---|
| ₀ | Subscript Zero | Copy / paste | Copy / paste | ₀ |
2080 + Alt+X |
U+2080 |
| ₁ | Subscript One | Copy / paste | Copy / paste | ₁ |
2081 + Alt+X |
U+2081 |
| ₂ | Subscript Two | Copy / paste | Copy / paste | ₂ |
2082 + Alt+X |
U+2082 |
| ₃ | Subscript Three | Copy / paste | Copy / paste | ₃ |
2083 + Alt+X |
U+2083 |
| ⁺ | Superscript Plus Sign | Copy / paste | Copy / paste | ⁺ |
207A + Alt+X |
U+207A |
| ⁻ | Superscript Minus | Copy / paste | Copy / paste | ⁻ |
207B + Alt+X |
U+207B |
| → | Rightwards Arrow | Alt+26 |
Copy / paste | → |
2192 + Alt+X |
U+2192 |
| ⇌ | Rightwards Harpoon Over Leftwards Harpoon | Copy / paste | Copy / paste | ⇌ |
21CC + Alt+X |
U+21CC |
| ↑ | Upwards Arrow | Alt+24 |
Copy / paste | ↑ |
2191 + Alt+X |
U+2191 |
| ↓ | Downwards Arrow | Alt+25 |
Copy / paste | ↓ |
2193 + Alt+X |
U+2193 |
| ∆ | Increment | Copy / paste | Option+J |
∆ |
2206 + Alt+X |
U+2206 |
| ° | Degree Sign | Alt+0176 |
Shift+Option+8 |
° |
00B0 + Alt+X |
U+00B0 |
Formatting or characters?
- Formatting (subscript/superscript) works for any digit or sign and looks best in documents. It disappears when pasted as plain text: H₂O becomes H2O.
- Unicode characters ₀–₉, ⁰–⁹, ⁺, ⁻ stay small everywhere. Good for chats, posts and titles. Not every font draws them well, and they cannot be searched as normal digits.
Formulas and ions
| Write | In a document | As plain-text characters |
|---|---|---|
| Water | H2O with 2 as subscript | H₂O |
| Carbon dioxide | CO2, 2 subscript | CO₂ |
| Sodium ion | Na+, + superscript | Na⁺ |
| Sulfate ion | SO4 2−, 4 subscript, 2− superscript | SO₄²⁻ |
| Iron(III) | Fe3+, 3+ superscript | Fe³⁺ |
The superscript ² and ³ have real Alt codes (Alt+0178, Alt+0179); see squared and cubed. The other superscripts and all subscripts do not.
Reaction arrows and other signs
- → yields:
Alt+26, or Word2192+ Alt+X. Some writers prefer the longer ⟶ (27F6). - ⇌ reversible reaction / equilibrium: Word
21CC+ Alt+X; LaTeX\rightleftharpoons. - ↑ ↓ gas given off, precipitate:
Alt+24,Alt+25. - ∆ heat (written above the arrow): Word
2206+ Alt+X; Mac Option+J. - ° standard state or temperature:
Alt+0176. - State symbols (s), (l), (g), (aq) are just letters in brackets; write them after each formula, often as subscript in printed work.
Word: the equation editor
For complete equations, Word's equation editor (Alt+=) handles subscripts with _ and superscripts with ^: typing H_2 O and a space produces a subscript 2. Equations are set in a maths font, which italicises letters; many chemists prefer normal text with subscript formatting for formulas. More Word methods: symbols in Word.
Phones
Phone keyboards have no subscript keys. Copy H₂O, CO₂ or the single characters from this page, and save the ones you use as text replacements (for example h2oo → H₂O).
Related: physics symbols, arrow symbols and our superscript and subscript characters.
Frequently asked questions
How do I type H₂O in Word or Google Docs?
Type H2O, select the 2 and apply subscript: Ctrl + = in Word, Ctrl + , in Google Docs (Command on a Mac). The formatting is lost if you paste the text into plain-text places.
How do I type H₂O in a chat or on social media?
Use the subscript character ₂ instead of formatting. Copy it from this page, or in Word type 2082 and press Alt+X, then copy the result.
How do I type the equilibrium arrow ⇌?
There is no Alt code. In Word type 21CC and press Alt+X, or use an equation with \rightleftharpoons. You can also copy ⇌ from this page.
Is there an Alt code for subscript numbers?
No real one. The subscript digits are U+2080 to U+2089, above code 255, and codes above 255 do not work in most Windows programs; they only work in programs built on Microsoft's RichEdit text control, such as WordPad.
Looking for something else? Browse 1,000+ copy-paste symbols, the full Alt Codes finder, or the emoji picker.