Which definition of H do you mean?

  • H n the 8th letter of the Roman alphabet
  • Heat Content n (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure
  • Henry n a unit of inductance in which an induced electromotive force of one volt is produced when the current is varied at the rate of one ampere per second
  • Hydrogen n a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe
  • Planck's Constant n the constant of proportionality relating the energy of a photon to its frequency; approximately 6.626 x 10^-34 joule-second