Interactive periodic table with up-to-date element property data collected from authoritative sources. Look up chemical element names, symbols, atomic masses and other properties, visualize trends, or even test your elements knowledge by playing a periodic table game!

Explore how density changes with atomic number in the periodic table of elements via interactive plots.

Explore how melting point changes with atomic number in the periodic table of elements via interactive plots.

Explore how boiling point changes with atomic number in the periodic table of elements via interactive plots.

Chemical element, Helium, information from authoritative sources. Look up properties, history, uses, and more.

PERIODIC TABLE OF ELEMENTS Chemical Group Block 17 Atomic Number Cl Symbol Chlorine Name Halogen Chemical Group Block 1 H Hydrogen Nonmetal 1 1 2 He Helium Noble Gas 18 3 Li Lithium Alkali Metal 2 4 Be Beryllium Alkaline Earth M … 2 5 B Boron Metalloid 13 6 C Carbon Nonmetal 14 7 N Nitrogen Nonmetal 15 8 O Oxygen Nonmetal 16 9 F Fluorine ...

PERIODIC TABLE OF ELEMENTS Electron Configuration 17 Atomic Number Cl Symbol Chlorine Name [Ne]3s 2 3p 5 Electron Configuration 1 H Hydrogen 1s 1 1 1 2 He Helium 1s 18 2 3 Li Lithium [He]2s 1 2 4 Be Beryllium [He]2s 2 2 5 B Boron [He]2s 2p 13 6 C Carbon [He]2s 2p 14 2 7 N Nitrogen [He]2s 2p 15 3 8 O Oxygen [He]2s 2p 16 2 4 9 F Fluorine [He]2s ...

Explore how ionization energy changes with atomic number in the periodic table of elements via interactive plots.

As we mark the 150th anniversary of the periodic table, the scientific community has declared 2019 to be “The International Year of the Periodic Table”. PubChem is celebrating by launching the PubChem Periodic Table and corresponding Element pages.

Explore how electron affinity changes with atomic number in the periodic table of elements via interactive plots.