Chemical Elements
Chemical elements and their symbols, weights, discovery years, and credited discoverers.
Download optionsThe records
10 of 118 records ยท Select a column heading to sort.
| ID | Element | Symbol | Weight | Discovered | Discovered by | Discovery notes | Weight type |
|---|---|---|---|---|---|---|---|
| 1 | Actinium | Ac | 227.0000 | 1899 | Andre-Louis Debierne | Isotope mass number | |
| 2 | Aluminum | Al | 26.9820 | 1825 | Hans Oersted | Standard atomic weight | |
| 3 | Americium | Am | 243.0000 | 1944 | Glenn Seaborg and colleagues | Isotope mass number | |
| 4 | Antimony | Sb | 121.7600 | Unknown | Known in antiquity; no single discovery year or discoverer is recorded. | Standard atomic weight | |
| 5 | Argon | Ar | 39.9500 | 1894 | Lord Rayleigh and Sir William Ramsay | Standard atomic weight | |
| 6 | Arsenic | As | 74.9220 | 1250 | Albertus Magnus | Approximate date in the RSC reference. | Standard atomic weight |
| 7 | Astatine | At | 210.0000 | 1940 | Dale R. Corson, Kenneth Ross MacKenzie, Emilio Segrè | Isotope mass number | |
| 8 | Barium | Ba | 137.3300 | 1808 | Humphry Davy | Standard atomic weight | |
| 9 | Berkelium | Bk | 247.0000 | 1949 | Stanley Thompson, Albert Ghiorso, and Glenn Seaborg | Isotope mass number | |
| 10 | Beryllium | Be | 9.0122 | 1798 | Louis Nicolas Vauquelin | Discovery announced in 1798; metal isolated independently by Friedrich Wohler and Antoine Bussy in 1828. | Standard atomic weight |
Scope and sources
Last changed: October 6, 2026. This may reflect a change to the data or its description; it is not a coverage-through date.
- CIAAW: Abridged Standard Atomic Weights 2024
- Royal Society of Chemistry: Periodic Table
- NIH PubChem: Periodic Table
- Jefferson Lab: Moscovium discovery
- Jefferson Lab: Oganesson discovery
A complete download includes all 118 records currently held in this dataset. Check the description and sources to decide whether its scope fits your project.
Use this dataset through the API
GET https://mysafeinfo.com/api/data/elementsChoose a format, sort, or request fewer rows. A pass key gives access to the complete dataset. See the examples and parameters.