# Periodic Table Element Lookup

> Periodic Table Element Lookup is a paid API for AI agents from chem.openverbs.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-09-14).

Look up a periodic-table element by symbol, name, or atomic number and return its atomic weight and metadata.

## Facts

- Endpoint: POST https://chem.openverbs.com/v1/element
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/periodic-table-element-lookup-7d214b0f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gVt3A5AGgbpW3yzxVTyGh

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability periodic-table-element-lookup-7d214b0f -d '<json body>'
```

Example prompt: What is the standard atomic weight of iron? Look it up by its symbol Fe and tell me the atomic number, name, and weight.

## When to prefer this

Use this endpoint when you need precise, structured periodic-table data for a single known element — identified by symbol, name, or atomic number — including its verified standard atomic weight. Prefer this over a search endpoint when you already know the exact identifier. For substring or partial-name searches, use the sibling search endpoint instead.

## Known failure modes

- Providing more than one lookup key (symbol, name, or number) simultaneously may result in an error or ambiguous response
- Atomic number out of range 1–118 returns a validation error
- Unknown or misspelled element name or symbol returns not-found error
- Element symbol or name longer than allowed character limits triggers schema validation failure

## How this service works

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.

## Output

Returns the element's atomic number (integer), symbol (e.g. 'Fe'), name (e.g. 'iron'), standard atomic weight as a numeric value, and a boolean indicating whether the weight is a true standard atomic weight (as opposed to a conventional or approximate value).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "bodyType",
    "body"
   ],
   "properties": {
    "body": {
     "type": "object",
     "properties": {
      "name": {
       "type": "string",
       "maxLength": 20,
       "minLength": 1,
       "description": "Element name, e.g. \"iron\"."
      },
      "number": {
       "type": "integer",
       "maximum": 118,
       "minimum": 1,
       "description": "Atomic number."
      },
      "symbol": {
       "type": "string",
       "maxLength": 3,
       "minLength": 1,
       "description": "Element symbol, e.g. \"Fe\"."
      }
     },
     "additionalProperties": false
    },
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "bodyType": {
     "enum": [
      "json",
      "form-data",
      "text"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/periodic-table-element-lookup-7d214b0f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from chem.openverbs.com](https://www.zero.xyz/host/chem.openverbs.com/llms.txt)