{
  "api": "physical-constants",
  "title": "Physical Constants",
  "description": "Fundamental physical constants with symbols, values and units.",
  "emoji": "🔬",
  "license": "GPL-2.0-or-later",
  "count": 25,
  "self": "https://gratisapi.com/api/physical-constants/index",
  "endpoints": {
    "list": "https://gratisapi.com/api/physical-constants/index",
    "item": "https://gratisapi.com/api/physical-constants/{id}"
  },
  "fields": [
    "category",
    "id",
    "name",
    "symbol",
    "unit",
    "value"
  ],
  "results": [
    {
      "id": "speed-of-light",
      "name": "Speed of light in vacuum",
      "symbol": "c",
      "value": 299792458.0,
      "unit": "m/s",
      "category": "Universal",
      "url": "https://gratisapi.com/api/physical-constants/speed-of-light"
    },
    {
      "id": "gravitational-constant",
      "name": "Newtonian constant of gravitation",
      "symbol": "G",
      "value": 6.6743e-11,
      "unit": "m^3 kg^-1 s^-2",
      "category": "Universal",
      "url": "https://gratisapi.com/api/physical-constants/gravitational-constant"
    },
    {
      "id": "planck-constant",
      "name": "Planck constant",
      "symbol": "h",
      "value": 6.62607015e-34,
      "unit": "J s",
      "category": "Universal",
      "url": "https://gratisapi.com/api/physical-constants/planck-constant"
    },
    {
      "id": "reduced-planck-constant",
      "name": "Reduced Planck constant",
      "symbol": "hbar",
      "value": 1.054571817e-34,
      "unit": "J s",
      "category": "Universal",
      "url": "https://gratisapi.com/api/physical-constants/reduced-planck-constant"
    },
    {
      "id": "elementary-charge",
      "name": "Elementary charge",
      "symbol": "e",
      "value": 1.602176634e-19,
      "unit": "C",
      "category": "Electromagnetic",
      "url": "https://gratisapi.com/api/physical-constants/elementary-charge"
    },
    {
      "id": "vacuum-permeability",
      "name": "Vacuum magnetic permeability",
      "symbol": "mu_0",
      "value": 1.25663706212e-06,
      "unit": "N A^-2",
      "category": "Electromagnetic",
      "url": "https://gratisapi.com/api/physical-constants/vacuum-permeability"
    },
    {
      "id": "vacuum-permittivity",
      "name": "Vacuum electric permittivity",
      "symbol": "epsilon_0",
      "value": 8.8541878128e-12,
      "unit": "F/m",
      "category": "Electromagnetic",
      "url": "https://gratisapi.com/api/physical-constants/vacuum-permittivity"
    },
    {
      "id": "coulomb-constant",
      "name": "Coulomb constant",
      "symbol": "k_e",
      "value": 8987551787.368176,
      "unit": "N m^2 C^-2",
      "category": "Electromagnetic",
      "url": "https://gratisapi.com/api/physical-constants/coulomb-constant"
    },
    {
      "id": "boltzmann-constant",
      "name": "Boltzmann constant",
      "symbol": "k_B",
      "value": 1.380649e-23,
      "unit": "J/K",
      "category": "Thermodynamic",
      "url": "https://gratisapi.com/api/physical-constants/boltzmann-constant"
    },
    {
      "id": "avogadro-constant",
      "name": "Avogadro constant",
      "symbol": "N_A",
      "value": 6.02214076e+23,
      "unit": "mol^-1",
      "category": "Physicochemical",
      "url": "https://gratisapi.com/api/physical-constants/avogadro-constant"
    },
    {
      "id": "gas-constant",
      "name": "Molar gas constant",
      "symbol": "R",
      "value": 8.314462618,
      "unit": "J mol^-1 K^-1",
      "category": "Physicochemical",
      "url": "https://gratisapi.com/api/physical-constants/gas-constant"
    },
    {
      "id": "faraday-constant",
      "name": "Faraday constant",
      "symbol": "F",
      "value": 96485.33212,
      "unit": "C/mol",
      "category": "Physicochemical",
      "url": "https://gratisapi.com/api/physical-constants/faraday-constant"
    },
    {
      "id": "stefan-boltzmann-constant",
      "name": "Stefan-Boltzmann constant",
      "symbol": "sigma",
      "value": 5.670374419e-08,
      "unit": "W m^-2 K^-4",
      "category": "Thermodynamic",
      "url": "https://gratisapi.com/api/physical-constants/stefan-boltzmann-constant"
    },
    {
      "id": "electron-mass",
      "name": "Electron mass",
      "symbol": "m_e",
      "value": 9.1093837015e-31,
      "unit": "kg",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/electron-mass"
    },
    {
      "id": "proton-mass",
      "name": "Proton mass",
      "symbol": "m_p",
      "value": 1.67262192369e-27,
      "unit": "kg",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/proton-mass"
    },
    {
      "id": "neutron-mass",
      "name": "Neutron mass",
      "symbol": "m_n",
      "value": 1.67492749804e-27,
      "unit": "kg",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/neutron-mass"
    },
    {
      "id": "atomic-mass-unit",
      "name": "Atomic mass constant",
      "symbol": "m_u",
      "value": 1.6605390666e-27,
      "unit": "kg",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/atomic-mass-unit"
    },
    {
      "id": "fine-structure-constant",
      "name": "Fine-structure constant",
      "symbol": "alpha",
      "value": 0.0072973525693,
      "unit": "dimensionless",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/fine-structure-constant"
    },
    {
      "id": "rydberg-constant",
      "name": "Rydberg constant",
      "symbol": "R_inf",
      "value": 10973731.56816,
      "unit": "m^-1",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/rydberg-constant"
    },
    {
      "id": "bohr-radius",
      "name": "Bohr radius",
      "symbol": "a_0",
      "value": 5.29177210903e-11,
      "unit": "m",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/bohr-radius"
    },
    {
      "id": "bohr-magneton",
      "name": "Bohr magneton",
      "symbol": "mu_B",
      "value": 9.2740100783e-24,
      "unit": "J/T",
      "category": "Atomic",
      "url": "https://gratisapi.com/api/physical-constants/bohr-magneton"
    },
    {
      "id": "electron-volt",
      "name": "Electron volt",
      "symbol": "eV",
      "value": 1.602176634e-19,
      "unit": "J",
      "category": "Physicochemical",
      "url": "https://gratisapi.com/api/physical-constants/electron-volt"
    },
    {
      "id": "standard-gravity",
      "name": "Standard acceleration of gravity",
      "symbol": "g_n",
      "value": 9.80665,
      "unit": "m/s^2",
      "category": "Adopted",
      "url": "https://gratisapi.com/api/physical-constants/standard-gravity"
    },
    {
      "id": "wien-displacement-constant",
      "name": "Wien wavelength displacement law constant",
      "symbol": "b",
      "value": 0.002897771955,
      "unit": "m K",
      "category": "Thermodynamic",
      "url": "https://gratisapi.com/api/physical-constants/wien-displacement-constant"
    },
    {
      "id": "planck-mass",
      "name": "Planck mass",
      "symbol": "m_P",
      "value": 2.176434e-08,
      "unit": "kg",
      "category": "Universal",
      "url": "https://gratisapi.com/api/physical-constants/planck-mass"
    }
  ]
}