Free Periodic Table Online
Free Periodic Table Online is a free online tool by US AI. Elements reference. It runs completely in your browser — no signup, no download, works on mobile and desktop.
📖 How to use
- Tap any element tile to see its atomic number, symbol, atomic mass and group. Tiles are colored by element group.
- Open the tool with the button above — it loads instantly.
- Your work stays on your device; nothing is uploaded anywhere.
✨ Why use this tool?
US AI's free periodic table online is fast, private and 100% free forever. Bookmark this page and share it with anyone who needs it.
🧪 Element groups at a glance
- Alkali metals: Group 1 — soft, highly reactive metals like sodium and potassium.
- Alkaline earth metals: Group 2 — reactive metals like calcium and magnesium, harder than alkali metals.
- Transition metals: Groups 3–12 — hard, conductive metals like iron, copper and gold.
- Post-transition metals: Softer, lower-melting metals like tin, lead and aluminium.
- Metalloids: Elements like silicon and boron with properties between metals and nonmetals.
- Nonmetals: Mostly gases and brittle solids like carbon, nitrogen and oxygen.
- Halogens: Group 17 — highly reactive nonmetals like chlorine and fluorine.
- Noble gases: Group 18 — almost completely unreactive gases like helium and neon.
- Lanthanides: The 15 rare-earth metals from lanthanum to lutetium, used in magnets and screens.
- Actinides: The 15 heavy elements from actinium to lawrencium, most of them radioactive.
❓ Frequently asked questions
How many elements are in the periodic table?
There are 118 confirmed elements, from hydrogen (atomic number 1) to oganesson (118). New elements are added only after rigorous scientific verification.
Who created the periodic table?
Russian chemist Dmitri Mendeleev published the first widely recognized periodic table in 1869. He ordered elements by atomic weight and left gaps for undiscovered ones — later refined by atomic number.
How is the periodic table organized?
Elements are ordered by atomic number into 7 horizontal rows called periods and 18 vertical columns called groups. Elements in the same group share similar chemical properties.
What do the numbers on each element tile mean?
The large number is the atomic number (the count of protons), the letters are the chemical symbol, and the decimal number is the atomic mass in atomic mass units.
What are groups and periods?
Groups are the vertical columns — elements in a group behave similarly because they have the same number of outer-shell electrons. Periods are the horizontal rows, showing electron shells filling up.
What are noble gases, halogens and alkali metals?
Alkali metals (group 1) are highly reactive soft metals. Halogens (group 17) are reactive nonmetals. Noble gases (group 18) are almost completely unreactive because their outer electron shells are full.
What is the most abundant element?
Hydrogen is the most abundant element in the universe, while oxygen is the most abundant in Earth's crust.
Can I use this periodic table for exams and homework?
Yes — it is free for study use. For exams, always cross-check with your textbook or teacher, since class conventions for rounding atomic masses can differ.