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, …

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 …

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

Search and explore chemical information in the world's largest free chemistry database. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and …

Periodic Table element Summary Helium. Helium is a chemical element with symbol He and atomic number 2. Classified as a noble gas, Helium is a gas at room temperature.

Periodic Table element Summary Cobalt. Cobalt is a chemical element with symbol Co and atomic number 27. Classified as a transition metal, Cobalt is a solid at room temperature.

Periodic Table element Summary Gallium. Gallium is a chemical element with symbol Ga and atomic number 31. Classified as a post-transition metal, Gallium is a solid at room temperature.

Periodic Table element Summary Oxygen. Oxygen is a chemical element with symbol O and atomic number 8. Classified as a nonmetal, Oxygen is a gas at room temperature.

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

Zinc is a bluish-white, lustrous metal. It is brittle at ordinary temperatures but malleable at 100 to 150°C. It is a fair conductor of electricity, and burns in air at high red heat with evolution of …