Chemical Element Symbols Copy and Paste

How element symbols are formed

An element symbol is one or two letters, occasionally three for the very newest. The first letter is always a capital and any letter after it is always lower case. That rule is not cosmetic: it is what lets a formula be read unambiguously. CO is carbon monoxide, one carbon and one oxygen, while Co is cobalt, a single atom of element 27.

Where the symbol has two letters, the second is normally the next distinctive letter of the name rather than simply the second letter, chosen to avoid a clash. Chlorine is Cl because C was already carbon. Magnesium is Mg and manganese is Mn because both start Ma.

Symbols are the same in every language. A German text writes Stickstoff for nitrogen and a French one writes azote, but both write N. That universality is exactly why IUPAC controls them.

• One capital letter only: H, B, C, N, O, F, P, S, K, V, Y, I, W, U.
• Capital plus lower case: He, Li, Be, Ne, Na, Mg, Al, Si, Cl, Ar, Ca and most of the rest.
• Never all caps. CO is a compound, Co is an element, and CO₂ written as Co₂ means something different and wrong.
• Isotopes put the mass number as a superscript in front: ¹⁴C, ²³⁵U, ³H.

The eleven symbols that come from Latin names

A handful of elements were known long before modern chemistry and kept symbols derived from their Latin (or in one case German) names. These are the ones students lose marks on, so they are worth learning as a set.

Tungsten is the odd one out in the list: W comes from wolfram, its German name, and much of the world still calls the element wolfram rather than tungsten.

• Fe, iron, from ferrum.
• Au, gold, from aurum.
• Ag, silver, from argentum.
• Cu, copper, from cuprum.
• Pb, lead, from plumbum (the same root as plumbing).
• Sn, tin, from stannum.
• Hg, mercury, from hydrargyrum, meaning water silver.
• Na, sodium, from natrium.
• K, potassium, from kalium.
• Sb, antimony, from stibium.
• W, tungsten, from wolfram.

Subscripts in formulas and superscripts on ions

In a chemical formula the number of atoms goes below the line: H₂O, CO₂, C₆H₁₂O₆, H₂SO₄, NaHCO₃. A subscript always applies to the symbol or bracketed group immediately before it, so Ca(OH)₂ has two hydroxide groups, not two hydrogens.

Charges go above the line, with the number before the sign: Na⁺, Cl⁻, Ca²⁺, SO₄²⁻, PO₄³⁻, Fe³⁺. A single charge is written as a bare plus or minus with no 1. Note the order in SO₄²⁻: subscript 4 for the four oxygens, then superscript 2 minus for the charge.

You can build these two ways. Paste the Unicode characters from the grids above, which keep working in plain text, file names, chat apps and spreadsheet cells, or use your editor's subscript formatting, which looks better in a typeset document but disappears the moment the text is copied somewhere plain. For anything that will be copied around, Unicode wins.

• Water: H₂O. Carbon dioxide: CO₂. Glucose: C₆H₁₂O₆. Ammonia: NH₃. Methane: CH₄.
• Sulfuric acid: H₂SO₄. Sodium bicarbonate: NaHCO₃. Calcium carbonate: CaCO₃.
• Common ions: Na⁺, K⁺, Ca²⁺, Mg²⁺, Fe²⁺, Fe³⁺, Cl⁻, OH⁻, NO₃⁻, SO₄²⁻, CO₃²⁻, PO₄³⁻.
• Hydrates use a middle dot: CuSO₄·5H₂O.

Typing formulas in Word, Google Docs and Excel

In Microsoft Word, CTRL plus = turns subscript on and off, and CTRL plus SHIFT plus + does the same for superscript. Type H, toggle subscript, type 2, toggle it off, type O. Word also accepts the code point plus ALT + X, so typing 2082 then ALT + X gives ₂.

Google Docs uses CTRL plus comma for subscript and CTRL plus full stop for superscript (CMD on a Mac). Insert then Special characters also works, and its handwriting search box finds any symbol on this page.

Excel is the awkward one. Cell formatting can apply subscript to part of a text cell (Format Cells, then Font, then Subscript), but the formatting is lost as soon as the cell is used in a formula or exported to CSV. In a spreadsheet, paste the Unicode subscripts from this page instead: they are characters, so they survive sorting, formulas, filters and CSV export.

On a Mac anywhere, CTRL plus CMD plus SPACE opens the Character Viewer, where searching for subscript two finds ₂. On Windows, the emoji panel opens with the Windows key plus full stop and has a symbols tab.

Symbols beyond the letters: arrows, hazards and units

A balanced equation needs more than element symbols. The plain arrow → means yields, the double harpoon ⇌ means the reaction is reversible and at equilibrium, and conditions such as heat (∆) or a catalyst are written above the arrow. An up arrow after a product marks a gas leaving the mixture and a down arrow marks a precipitate.

Units bring their own characters: the degree sign in 25 °C (with a space before it in SI style), the micro sign µ for micromolar, the angstrom Å for bond lengths, the ohm Ω for resistance and the per mille sign ‰ for isotope ratios. The single-character forms ℃ and ℉ exist for compatibility, but a degree sign followed by a plain C is generally preferred in typesetting.

Safety labels use the trefoil ☢ for radioactivity and ☣ for biohazard. The atom symbol ⚛ and the alembic ⚗ are decorative rather than technical, and both are popular in titles, profiles and slide headers.

The newest elements and their names

The periodic table's seventh row was completed in 2016, when IUPAC approved names for the last four gaps. Nihonium (Nh, 113) is named for Nihon, one of the Japanese names for Japan, and was the first element discovered by a team in Asia. Moscovium (Mc, 115) and tennessine (Ts, 117) honour the Moscow region and the state of Tennessee, home to the laboratories involved. Oganesson (Og, 118) honours the physicist Yuri Oganessian, only the second element named after a living person.

Just before them came copernicium (Cn, 112) in 2010, flerovium (Fl, 114) and livermorium (Lv, 116) in 2012. All of these are synthesised an atom at a time in accelerators and decay in milliseconds or less, so their chemistry is barely explored.

Elements that have been claimed but not yet confirmed and named get a temporary systematic symbol built from their digits: element 119 would be ununennium, Uue, until it earns a real name. IUPAC naming convention now ends every group 17 element in -ine and every group 18 element in -on, which is why it is tennessine and oganesson.