PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, …

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!

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

PubChem homepage provides a quick search functionality allowing many different input types in a single search box and providing results accross multiple data collections.

Google Patents provides patent information to the public via BigQuery tables. PubChem imports this information, and contains links between 31 million chemical structures and the 25 million patent documents that mention them.

An attractive and highly valued metal, gold has been known for at least 5500 years. Gold is sometimes found free in nature but it is usually found in conjunction with silver, quartz (SiO 2), calcite (CaCO 3), lead, tellurium, zinc or copper.There is roughly 1 milligram of gold dissolved in every ton of seawater, although extracting it currently costs more than the gold is worth.

The element has two allotropic forms at normal pressure. On warming, gray, or alpha tin, with a cubic structure, changes at 13.2°C into white, or beta tin, the ordinary form of the metal.

Note: This page provides the current GHS summary. Obsolete [(marked as) deleted in GHS Rev.10 2023 PDF document] H-codes and P-codes are also provided, as they are still in use but annotated as obsolete. For more information, please see the References. This is the permanent link to the GHS 2023 (Rev. 10) summary.Please also see the previous GHS 2021 (Rev. 9) …

The name derives from the Greek argos for "lazy" or "inactive" because it does not combine with other elements. It was discovered in 1894 by the Scottish chemist William Ramsay and the English physicist Robert John Strutt (Lord Rayleigh) in liquefied air.

Calcium (Ca2+) plays a pivotal role in the physiology and biochemistry of organisms and the cell. It plays an important role in signal transduction pathways, where it acts as a second messenger, in neurotransmitter release from neurons, contraction of all muscle cell types, and fertilization.