How Many Elements Are in the Periodic Table? All 118 (2026)

There are 118 known elements in the periodic table in 2026. The list runs from hydrogen, atomic number 1, to oganesson, atomic number 118. The American Chemical Society gives the same total and explains the organizing rule: elements appear in order of increasing atomic number.

If you came here for a quick lookup, the complete table is directly below. It gives every element name, exact case-sensitive symbol, and atomic number—without atomic weights mixed into the same reference. After the table, there is a practical way to decide which of those facts your course actually requires and turn only that scope into flashcards.

Facts checked: September 6, 2026.

All 118 elements: atomic numbers, symbols, and names

The number-symbol-name sequence below was cross-checked against the NIST Periodic Table of the Elements and the IUPAC reference table. The spelling column follows NIST's U.S. English: aluminum and cesium. IUPAC uses aluminium and caesium. Neither choice changes Al, Cs, 13, or 55, so use the spelling your course expects.

Atomic number	Symbol	Element name
1	H	Hydrogen
2	He	Helium
3	Li	Lithium
4	Be	Beryllium
5	B	Boron
6	C	Carbon
7	N	Nitrogen
8	O	Oxygen
9	F	Fluorine
10	Ne	Neon
11	Na	Sodium
12	Mg	Magnesium
13	Al	Aluminum
14	Si	Silicon
15	P	Phosphorus
16	S	Sulfur
17	Cl	Chlorine
18	Ar	Argon
19	K	Potassium
20	Ca	Calcium
21	Sc	Scandium
22	Ti	Titanium
23	V	Vanadium
24	Cr	Chromium
25	Mn	Manganese
26	Fe	Iron
27	Co	Cobalt
28	Ni	Nickel
29	Cu	Copper
30	Zn	Zinc
31	Ga	Gallium
32	Ge	Germanium
33	As	Arsenic
34	Se	Selenium
35	Br	Bromine
36	Kr	Krypton
37	Rb	Rubidium
38	Sr	Strontium
39	Y	Yttrium
40	Zr	Zirconium
41	Nb	Niobium
42	Mo	Molybdenum
43	Tc	Technetium
44	Ru	Ruthenium
45	Rh	Rhodium
46	Pd	Palladium
47	Ag	Silver
48	Cd	Cadmium
49	In	Indium
50	Sn	Tin
51	Sb	Antimony
52	Te	Tellurium
53	I	Iodine
54	Xe	Xenon
55	Cs	Cesium
56	Ba	Barium
57	La	Lanthanum
58	Ce	Cerium
59	Pr	Praseodymium
60	Nd	Neodymium
61	Pm	Promethium
62	Sm	Samarium
63	Eu	Europium
64	Gd	Gadolinium
65	Tb	Terbium
66	Dy	Dysprosium
67	Ho	Holmium
68	Er	Erbium
69	Tm	Thulium
70	Yb	Ytterbium
71	Lu	Lutetium
72	Hf	Hafnium
73	Ta	Tantalum
74	W	Tungsten
75	Re	Rhenium
76	Os	Osmium
77	Ir	Iridium
78	Pt	Platinum
79	Au	Gold
80	Hg	Mercury
81	Tl	Thallium
82	Pb	Lead
83	Bi	Bismuth
84	Po	Polonium
85	At	Astatine
86	Rn	Radon
87	Fr	Francium
88	Ra	Radium
89	Ac	Actinium
90	Th	Thorium
91	Pa	Protactinium
92	U	Uranium
93	Np	Neptunium
94	Pu	Plutonium
95	Am	Americium
96	Cm	Curium
97	Bk	Berkelium
98	Cf	Californium
99	Es	Einsteinium
100	Fm	Fermium
101	Md	Mendelevium
102	No	Nobelium
103	Lr	Lawrencium
104	Rf	Rutherfordium
105	Db	Dubnium
106	Sg	Seaborgium
107	Bh	Bohrium
108	Hs	Hassium
109	Mt	Meitnerium
110	Ds	Darmstadtium
111	Rg	Roentgenium
112	Cn	Copernicium
113	Nh	Nihonium
114	Fl	Flerovium
115	Mc	Moscovium
116	Lv	Livermorium
117	Ts	Tennessine
118	Og	Oganesson

IUPAC formally approved the names and symbols Nh, Mc, Ts, and Og for elements 113, 115, 117, and 118 in November 2016. That IUPAC naming announcement is useful when an old worksheet still shows temporary three-letter symbols.

Atomic number is not atomic mass

An element square can show several numbers, but they answer different questions.

• Atomic number identifies the element and equals its number of protons. Sodium is always atomic number 11.
• Element symbol is the one- or two-letter abbreviation. Case is part of the notation: sodium is Na, not NA or na.
• Atomic mass and atomic weight are not atomic number. Classroom tables may use either term around the larger decimal, but the terms are not perfectly interchangeable; follow the table's exact label, precision, and convention.
• Mass number is the whole-number total of protons and neutrons in one nuclide.

A bracketed whole number shown for a radioactive element on some tables is usually a mass number—not another atomic number or a standard atomic weight.

That is why the lookup above stops at name, symbol, and atomic number. Those three fields answer the search intent cleanly. NIST’s periodic-table version history also shows why a deck of precise atomic-weight values needs a source and date: the underlying reference data can be revised. If your course tests atomic weights, copy the exact property, table edition, and rounding rule it assigns.

How to memorize the periodic table: start with your course

Seeing 118 rows can create an assignment your course never made: “I suppose I have to memorize all of this.” The real scope is often narrower. Check the syllabus, teacher instructions, permitted reference sheet, and recent questions before making a deck.

If your work asks you to…	Useful recall target	Keep outside this deck
identify common elements in formulas	symbol → name	full formula writing and nomenclature problems
write symbols from element names	name → exact-case symbol	compound charges and subscripts
know the first 20 elements	the required direction for elements 1–20	the other 98 until the course reaches them
reconstruct the table	selected identities plus group/period anchors	repeated blank-table practice
compare periodic trends	a small set of direction rules and named exceptions	explanations and unfamiliar comparisons
write electron configurations	course-required configurations and exceptions	the orbital-filling work used to derive them
recall all 118 element identities	the tested directions for names, symbols, and atomic numbers	masses, trends, and configurations unless separately required

Teachers can remove a lot of ambiguity by stating the tested direction. “Know the elements” might mean reading a symbol, producing a symbol, filling a blank table, or recalling atomic numbers. Those tasks produce very different card counts.

Make cards from the error, not from the entire square

Co is cobalt. CO is a formula containing the separate symbols C and O. One lowercase letter changes what the notation says. A useful repair card targets that exact mistake:

Front: Which element has the symbol Co?
Back: Cobalt.

Front: In CO, which two element symbols are present?
Back: C for carbon and O for oxygen.

The second prompt is formula-reading practice, not another cobalt card. Other lookalikes include S and Si, N and Ni, C and Ca, and P and Pb. Keep the second letter of a two-letter symbol lowercase.

Some symbols are hard for a different reason: the English name does not supply the obvious letters. These are good candidates for early error-driven cards if they are in scope:

Element	Symbol	Atomic number
Sodium	Na	11
Potassium	K	19
Iron	Fe	26
Copper	Cu	29
Silver	Ag	47
Tin	Sn	50
Antimony	Sb	51
Tungsten	W	74
Gold	Au	79
Mercury	Hg	80
Lead	Pb	82

Do not make all eleven just because they are in this list. Try a blank-table or symbol quiz first, then keep the ones you miss.

One fact per card keeps grading honest

“Tell me everything about sodium” looks efficient because it fits one card. During review, it becomes awkward: perhaps you remembered Na and 11 but put it in the wrong period. A partly correct answer is hard to grade honestly.

Split the tested facts instead:

Front: Write the symbol for sodium. Preserve letter case.
Back: Na.

Front: Which element has the symbol Na?
Back: Sodium.

Front: Which element has atomic number 11?
Back: Sodium.

These are three directions, not three mandatory cards. Start with the direction that appears in your work. Add the reverse only when you must retrieve the reverse answer or when practice exposes a gap. Automatically reversing every fact can turn 118 elements into hundreds of reviews without improving the skill your assessment uses.

For broader card-design examples, see How to Make Better Flashcards.

A practical plan for memorizing your required set

Start with evidence, even if it is only a five-minute self-test.

1. Write down the exact scope. “Elements 1–20, name ↔ symbol” is usable. “Learn the periodic table” is not.
2. Take a short pretest without notes. Use a blank table, a teacher quiz, or a current chemistry problem. Mark each exact miss.
3. Make one card per missing direction. Do not create atomic-number, group, mass, and trend cards unless those facts are required.
4. Learn one bounded block. A course unit, a family, or elements 1–20 gives you a visible finish line. If all 118 are required, use small numbered bands instead of loading everything on day one.
5. Mix confusable items after they are individually familiar. Put Co, C, and O in the same practice session; mix neighboring atomic numbers that keep swapping. Nibomo does not create these contrasts automatically, so choose the deck order or tags yourself.
6. Rebuild the shape outside the deck. Fill a blank table and say the group or period anchors aloud. Isolated cards do not teach spatial layout by themselves.
7. Return to chemistry. Read formulas, explain a trend, write an electron configuration, and solve unfamiliar problems. Each repeated error can produce one small repair card.

Keep the daily queue realistic while expanding the set. How Many New Flashcards per Day? explains how to use your due-review load, rather than ambition, to set the intake.

Ready-made decks for three different jobs

If all 118 identities really are your target, the installable Periodic Table Flashcards: All 118 Names, Symbols & Atomic Numbers deck contains 354 cards. It uses three explicit directions for each element: name → symbol, symbol → name, and atomic number → complete element identity. It excludes atomic weights, spatial layout, trends, and electron configurations, so it stays an identity-recall deck instead of trying to become a chemistry course.

Two separate decks cover different scopes:

• Periodic Trends Flashcards covers concise trend rules, important distinctions, and comparisons.
• Electron Configuration Flashcards: All 118 Elements covers neutral-atom ground-state configurations, including clearly labeled predictions where the reference data requires them.

Metric prefixes are another nearby source of case errors—M and m do not mean the same thing—but they are not periodic-table content. Keep them in the separate Metric Prefix Flashcards guide so chemistry notation does not become one giant mixed deck.

What periodic table flashcards cannot teach

Flashcards are good at keeping a precise mapping available: Fe → iron, 26 → iron, or “sodium” → Na. They are much weaker as the only practice for connected work.

Keep doing these outside the deck:

• rebuild positions on a blank periodic table
• read the table legend and use the edition supplied in class
• explain why a trend occurs and handle the exceptions taught in your course
• write and interpret formulas and equations
• derive electron configurations instead of only recognizing finished ones
• solve calculations and unfamiliar multi-step problems
• complete laboratory work with the required supervision and safety procedures

The advanced chemistry flashcards guide develops this split between compact recall and full problem practice.

Where Nibomo fits

Nibomo supports ordinary front/back cards, decks, tags, and FSRS due reviews with Again, Hard, Good, and Easy ratings. You can install the 118-element deck or make a smaller deck that matches your course.

AI chat and file attachments can help draft candidate cards from a lesson table or a list of misses. Check every name, symbol, atomic number, property label, and rounding rule against your controlling source before saving. The app has no dedicated chemistry verifier and does not automatically interleave topics for you. The Getting Started guide covers creating cards and beginning due reviews.

Periodic table FAQ

How many elements are in the periodic table in 2026?

There are 118 known elements. Hydrogen is number 1 and oganesson is number 118. Current ACS, NIST, and IUPAC tables all end at element 118.

What is the 118th element?

Oganesson, symbol Og, is element 118. IUPAC approved its current name and symbol in November 2016 alongside nihonium (Nh), moscovium (Mc), and tennessine (Ts).

Should students memorize all 118 elements?

Only if the course or exam requires all 118. Many students need a smaller set, such as elements 1–20, common elements in formulas, selected families, or the current unit. Confirm the direction too: recognizing Na and writing it from “sodium” are separate skills.

Is atomic number the same as atomic mass?

No. Atomic number is the proton count and identifies the element. Mass number counts protons and neutrons in one nuclide; atomic mass and atomic weight describe different mass-related quantities. Use the exact term and reference specified by your course.

What is the fastest way to learn element names and symbols?

Define the smallest required set, test it without notes, and make cards only for missing directions. Then check recall with a blank table and real chemistry questions.

Use the table, then close it

Use the 118-row table when you need a trustworthy lookup. For recall, hide it, test exactly what your course expects, and make small cards from the misses. Then return to the blank table, formula, trend explanation, or calculation—the place where the knowledge has to work.