Molar mass
chem.openverbs.com · 3 paid endpoints · listed 2026-10-27
Look up a periodic-table element by exactly one of `symbol` (e.g. "Fe"), `name` (e.g. "iron") or atomic `number` (1..118). Returns its number, symbol, name, standard atomic weight and whether that weight is a true standard atomic weight.
Paid endpoints
| Method | Endpoint | Price | Networks |
|---|---|---|---|
| POST | chem.openverbs.com/v1/element Look up a periodic-table element by exactly one of `symbol` (e.g. "Fe"), `name` (e.g. "iron") or atomic `number` (1..118). Returns its number, symbol, name, sta | $0.004 | Base |
| POST | chem.openverbs.com/v1/molar-mass Compute the molar mass (g/mol) of a chemical formula. Supports nested parentheses and brackets, element multipliers, and hydrate dot notation with coefficients | $0.004 | Base |
| POST | chem.openverbs.com/v1/search Search the periodic table by name or symbol substring. Exact matches rank first, then prefix matches, then substring matches. Returns up to `limit` elements (de | $0.004 | Base |
Latest checks
| When | Endpoint | HTTP | ms | Result |
|---|---|---|---|---|
| 5 days ago | chem.openverbs.com/v1/element | 402 | 620 | valid x402 v2 terms |
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