Math & Numbers

Half-Life Activity Decay Calculator (A = A₀·e^(−λt))

Compute remaining radionuclide activity A(t) = A₀·2^(−t/T½) with λ = ln2/T½ in Bq/Ci/dpm units, for Tc-99m, F-18 and other isotopes.

json· JSON resultOpen tool

Quick start

Call this tool from your code in three languages.

cURL

curl -X POST 'http://127.0.0.1:3003/en/api/tools/half-life-activity-decay' \
  -H 'Content-Type: application/json' \
  -d '{"initialActivity":800,"activityUnit":"MBq","halfLife":6.01,"halfLifeUnit":"hours","elapsedTime":6,"timeUnit":"hours","decimalPlaces":2}'

API reference

Send a POST request with your inputs as JSON. File parameters require a separate upload first.

Endpoint

HTTP

POST http://127.0.0.1:3003/en/api/tools/half-life-activity-decay

Parameters

Name	Type	Required	Description
initialActivity	number	Yes	Activity at t = 0 in the selected activity unit. Must be non-negative.
activityUnit	select	Yes	Unit of the initial (and remaining) activity.
halfLife	number	Yes	Physical half-life in the selected time unit. Must be greater than zero.
halfLifeUnit	select	Yes	Time unit of the half-life.
elapsedTime	number	Yes

MCP integration

Add this tool to your Model Context Protocol server so AI agents can list and call it.

Server configuration

Add this block to your MCP client configuration:

mcp.json

{
  "mcpServers": {
    "elysiatools-half-life-activity-decay": {
      "name": "half-life-activity-decay",
      "description": "Compute remaining radionuclide activity A(t) = A₀·2^(−t/T½) with λ = ln2/T½ in Bq/Ci/dpm units, for Tc-99m, F-18 and other isotopes.",
      "baseUrl": "http://127.0.0.1:3003/mcp/sse?toolId=half-life-activity-decay",
      "command": "",
      "args": [],
      "env": {},
      "isActive": true,
      "type": "sse"
    }
  }
}

List available tools

After connecting to the SSE endpoint, list the exposed tools:

tools/list

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/list"
}

Call this tool

Invoke the tool by its id, passing arguments built from its parameters:

tools/call

{
  "jsonrpc": "2.0",
  "id": 2,
  "method": "tools/call",
  "params": {
    "name": "half-life-activity-decay",
    "arguments": {
  "initialActivity": 800,
  "activityUnit": "MBq",
  "halfLife": 6.01,
  "halfLifeUnit": "hours",
  "elapsedTime": 6,
  "timeUnit": "hours",
  "decimalPlaces": 2
}
  }
}

Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).

Questions or issues? Contact [email protected]

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