Periodic Table Symbols: Complete Guide to All 118 Elements and Their Symbols

The periodic table symbols are the short chemical abbreviations used to identify the 118 known chemical elements. Every element has a unique symbol, such as H for hydrogen, O for oxygen, C for carbon, Fe for iron, and Au for gold.

These symbols are more than simple abbreviations. They are used throughout chemistry to write chemical formulas, equations, compounds, laboratory results, and scientific information. Understanding them makes it much easier to read and use the periodic table.

This guide covers the complete list of periodic table symbols, their atomic numbers, capitalization rules, unusual symbols based on Latin names, the difference between an element symbol and a chemical formula, and practical ways to memorize them. It also answers common questions students have when learning chemical symbols.

What Are Periodic Table Symbols?

A periodic table symbol is a standardized one- or two-letter abbreviation that represents a chemical element. The symbol allows scientists and students to identify an element without writing its complete name.

For example:

• H = Hydrogen
• He = Helium
• Li = Lithium
• C = Carbon
• N = Nitrogen
• O = Oxygen
• Na = Sodium
• Cl = Chlorine
• Fe = Iron
• Au = Gold

The periodic table is arranged by increasing atomic number, while each element’s symbol provides a quick way to identify it. An element’s atomic number is the number of protons in the nucleus of its atoms.

How Many Periodic Table Symbols Are There?

There are 118 officially recognized chemical elements, so there are 118 corresponding element symbols.

The elements range from:

• Atomic number 1: Hydrogen (H)
• Atomic number 2: Helium (He)
• Atomic number 3: Lithium (Li)

all the way to:

• Atomic number 118: Oganesson (Og)

The complete list is useful for students who need to memorize symbols, identify elements from their abbreviations, or understand chemical formulas.

Complete List of Periodic Table Symbols

The table below provides the atomic number, element name, and chemical symbol for all 118 elements.

Rules for Writing Chemical Symbols

Chemical symbols follow specific capitalization rules. Learning these rules is essential because changing the capitalization can change the meaning.

One-Letter Element Symbols

When an element has a one-letter symbol, that letter is always uppercase.

Examples include:

• Hydrogen — H
• Boron — B
• Carbon — C
• Nitrogen — N
• Oxygen — O
• Fluorine — F
• Phosphorus — P
• Sulfur — S
• Potassium — K
• Vanadium — V
• Yttrium — Y
• Iodine — I
• Uranium — U

Writing a one-letter symbol in lowercase is incorrect.

For example, the correct symbol is C, not c.

Two-Letter Element Symbols

For a two-letter symbol, the first letter is uppercase and the second letter is lowercase.

Examples:

• Helium — He
• Lithium — Li
• Beryllium — Be
• Neon — Ne
• Sodium — Na
• Magnesium — Mg
• Aluminum — Al
• Silicon — Si
• Chlorine — Cl
• Calcium — Ca
• Iron — Fe

This capitalization rule is important when writing chemical formulas and equations. Element-symbol conventions use an uppercase first letter and a lowercase second letter when a second letter is present.

Why Do Some Element Symbols Look Different From Their Names?

One of the most confusing parts of learning periodic table symbols is that some symbols do not appear to match the modern English name of the element.

This is because several symbols come from historical names, especially Latin names.

Sodium — Na

The symbol for sodium is Na, rather than “S.” It comes from the Latin name natrium.

Potassium — K

Potassium is represented by K. The symbol comes from the Latin name kalium.

Iron — Fe

Iron has the symbol Fe, which comes from the Latin word ferrum.

Copper — Cu

Copper uses Cu, derived from the Latin cuprum.

Silver — Ag

Silver is represented by Ag, from argentum.

Gold — Au

Gold has the symbol Au, from the Latin aurum.

Mercury — Hg

Mercury is represented by Hg, connected to the historical name hydrargyrum.

Tin — Sn

Tin uses Sn, from the Latin stannum.

Antimony — Sb

Antimony has the symbol Sb, derived from stibium.

Tungsten — W

Tungsten is represented by W, based on the name wolfram.

Lead — Pb

Lead has the symbol Pb, from the Latin plumbum.

These historical symbols are among the most important exceptions for students to memorize. Chemistry learning resources commonly highlight these Latin-derived symbols because they cannot always be guessed from the English element names.

Most Important Periodic Table Symbols to Memorize

Students do not always need to memorize all 118 symbols immediately. A better approach is to begin with frequently encountered elements.

Common Nonmetals

Some important nonmetal symbols are:

These elements appear frequently in basic chemistry and chemical formulas.

Common Metals

Important metal symbols include:

Common Noble Gases

The noble gases have these symbols:

• Helium — He
• Neon — Ne
• Argon — Ar
• Krypton — Kr
• Xenon — Xe
• Radon — Rn
• Oganesson — Og

Knowing these groups can make the periodic table easier to study because you can learn symbols in related sets rather than as 118 unrelated facts.

Periodic Table Symbols and Atomic Numbers

A chemical symbol and an atomic number provide two different pieces of information.

The symbol identifies the element, while the atomic number tells you how many protons are in its nucleus.

For example:

The atomic number also determines which element an atom is. If an atom has six protons, it is carbon regardless of its charge or number of neutrons.

How Periodic Table Symbols Are Used in Chemical Formulas

Element symbols become especially useful when writing chemical formulas.

A chemical formula combines symbols to show what elements are present in a substance.

Water

Water is written as:

H₂O

It contains two hydrogen atoms and one oxygen atom.

Carbon Dioxide

Carbon dioxide is:

CO₂

It contains one carbon atom and two oxygen atoms.

Sodium Chloride

Common table salt is:

NaCl

The formula contains sodium and chlorine.

Calcium Carbonate

Calcium carbonate is:

CaCO₃

Its formula contains calcium, carbon, and oxygen.

Ammonia

Ammonia is:

NH₃

It contains nitrogen and hydrogen.

Methane

Methane is:

CH₄

It contains carbon and hydrogen.

This is why learning element symbols is an important foundation for understanding chemical formulas.

Element Symbols vs. Chemical Formulas

These two terms are related but not identical.

An element symbol represents a particular chemical element.

For example:

O = oxygen

A chemical formula represents a substance and can contain one or more element symbols.

For example:

O₂ = oxygen gas

and:

H₂O = water

The small number written after a symbol is called a subscript. It indicates how many atoms of that element are represented in the formula.

For example, in CO₂, the subscript 2 applies to oxygen, meaning there are two oxygen atoms for every one carbon atom.

How to Read a Periodic Table Cell

A typical periodic table cell contains more than just the element symbol. Depending on the table, you may see the atomic number, symbol, element name, and relative atomic mass.

For example, a simplified cell might look like:

8
O
Oxygen
16.00

Here:

• 8 is the atomic number.
• O is the chemical symbol.
• Oxygen is the element name.
• 16.00 is its approximate atomic mass.

The exact layout can vary between periodic tables, but the symbol is usually displayed prominently because it is the standard shorthand for the element.

Commonly Confused Periodic Table Symbols

Some symbols are easy to confuse because their letters look similar or their element names sound alike.

C, Ca, and Cd

• C = Carbon
• Ca = Calcium
• Cd = Cadmium

Co and Cu

• Co = Cobalt
• Cu = Copper

Cl and Cr

• Cl = Chlorine
• Cr = Chromium

N, Ne, Ni, and Nb

• N = Nitrogen
• Ne = Neon
• Ni = Nickel
• Nb = Niobium

S, Si, Sc, and Se

• S = Sulfur
• Si = Silicon
• Sc = Scandium
• Se = Selenium

Paying attention to the second letter is therefore just as important as remembering the first letter.

How to Memorize Periodic Table Symbols Faster

Memorizing 118 symbols can feel overwhelming, but breaking the task into smaller sections makes it much easier.

Start With the First 20 Elements

The first 20 elements are a good starting point because they are commonly taught in introductory chemistry.

Once these are familiar, continue with the remaining elements.

Use Two-Way Practice

Do not only practice:

Element → Symbol

Also practice:

Symbol → Element

For example:

Gold → Au

and then:

Au → Gold

This helps you recognize symbols when they appear in formulas, equations, tests, or a periodic table.

Learn the Exceptions Separately

Create a short list of unusual symbols:

Na, K, Fe, Cu, Ag, Sn, Sb, W, Au, Hg, Pb

These are worth extra practice because the symbols cannot always be predicted from their English names.

Use Flashcards and Quizzes

Flashcards, matching games, and short quizzes can help turn memorization into active recall. Online learning resources commonly use quizzes and printable worksheets specifically for practicing element symbols.

Instead of looking at a list repeatedly, cover the answers and try to recall them yourself.

A Simple Periodic Table Symbols Practice Quiz

Try answering these questions without looking at the table above.

Questions

1. What is the symbol for oxygen?
2. Which element has the symbol Fe?
3. What is the symbol for gold?
4. Which element is represented by Na?
5. What is the symbol for calcium?
6. Which element has the symbol Ag?
7. What is the symbol for potassium?
8. Which element is represented by Cu?
9. What is the symbol for chlorine?
10. Which element has the symbol Pb?

Answers

1. Oxygen = O
2. Fe = Iron
3. Gold = Au
4. Na = Sodium
5. Calcium = Ca
6. Ag = Silver
7. Potassium = K
8. Cu = Copper
9. Chlorine = Cl
10. Pb = Lead

Practicing both directions—name to symbol and symbol to name—is useful because students encounter both types of questions in chemistry exercises.

Why Capitalization Matters in Chemistry

Capitalization is not simply a writing preference in chemistry. It helps distinguish different element symbols.

For example:

Co means cobalt.

The letters C and O can separately represent carbon and oxygen when used as individual symbols, but Co is the symbol for cobalt.

Similarly:

Cl = chlorine

while:

C = carbon

Therefore, writing symbols correctly is essential when reading or creating chemical formulas.

Are Periodic Table Symbols the Same Worldwide?

Chemical symbols are standardized internationally, which allows scientists around the world to communicate chemical information using the same symbols.

Element names can have different spellings or pronunciations in different languages, but the chemical symbol remains a common scientific shorthand.

For example, Fe identifies iron regardless of the language being used to discuss the element.

This international standardization is one of the major reasons chemical symbols are so useful in science.

Tips for Students Studying Periodic Table Symbols

If you are preparing for a chemistry test, focus on understanding rather than simply copying a large list.

Focus on the First 20

Make sure you can quickly identify the first 20 elements and their symbols.

Memorize the Unusual Ones

Spend extra time on:

Na, K, Fe, Cu, Ag, Sn, Sb, W, Au, Hg, Pb

Practice Every Day

Even five to ten minutes of daily practice can be more effective than trying to memorize the entire periodic table in one sitting.

Write Symbols Correctly

Remember:

First letter = uppercase

Second letter = lowercase

Examples:

• Correct: Na
• Incorrect: NA
• Correct: Fe
• Incorrect: FE
• Correct: Cl
• Incorrect: CL

Practice With Chemical Formulas

Once you know symbols, try identifying the elements in formulas such as H₂O, CO₂, NaCl, CH₄, NH₃, and CaCO₃.

This connects memorization with actual chemistry.

Frequently Asked Questions About Periodic Table Symbols

What are periodic table symbols?

Periodic table symbols are standardized one- or two-letter abbreviations used to represent chemical elements. Examples include H for hydrogen, O for oxygen, and Fe for iron.

How many element symbols are on the periodic table?

There are 118 element symbols, corresponding to the 118 officially recognized chemical elements.

What is the symbol for hydrogen?

The symbol for hydrogen is H, and its atomic number is 1.

What is the symbol for oxygen?

The symbol for oxygen is O, and its atomic number is 8.

What is the symbol for carbon?

Carbon has the symbol C and atomic number 6.

What is the symbol for sodium?

Sodium is represented by Na. The symbol comes from the historical name natrium.

What is the symbol for potassium?

Potassium has the symbol K, which comes from the historical name kalium.

Why is iron Fe instead of I?

Iron’s symbol Fe comes from its Latin name ferrum. The letter I is already associated with iodine.

Why is gold called Au on the periodic table?

Gold is represented by Au, derived from the Latin word aurum.

What is the symbol for silver?

Silver has the symbol Ag, derived from the Latin word argentum.

Is the second letter of an element symbol lowercase?

Yes. If an element has a two-letter symbol, the first letter is uppercase and the second is lowercase, such as He, Na, Fe, Cl, and Au.

What is the difference between an element symbol and a chemical formula?

An element symbol identifies one element, while a chemical formula represents a substance and can contain multiple element symbols. For example, O represents oxygen, while H₂O represents water.

What are the hardest periodic table symbols to memorize?

Students often find symbols such as Na, K, Fe, Cu, Ag, Sn, Sb, W, Au, Hg, and Pb more difficult because they come from historical or Latin names rather than directly matching their modern English names.

Final Thoughts

Learning periodic table symbols is one of the most important foundations of chemistry. Every one of the 118 recognized elements has a unique symbol, and these symbols are used to write formulas, equations, scientific descriptions, and laboratory information.

The easiest way to learn them is to start with the first 20 elements, understand the capitalization rules, memorize the unusual historical symbols, and practice recognizing symbols in both directions.

Once symbols such as H, O, C, Na, Cl, Fe, Cu, Ag, and Au become familiar, reading chemical formulas becomes much easier. From there, gradually learning the remaining symbols will give you a much stronger understanding of the periodic table and basic chemistry.

Marcus Lee

I am Marcus Lee, a cultural researcher and slang aficionado. I study the roots of informal language and how communities create meaning through words. My books “Slang Origins: A Journey Through Words” and “Words That Move Us: Slang Across Generations” focus on the history and psychology of slang. I enjoy guiding readers to understand not just the words, but the stories and attitudes they carry, so you can truly connect with language in daily life.