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 …

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 …

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

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

Explore how atomic radius 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.

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

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

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

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