1. The 8th letter of the Roman alphabet
   - H
    
2. The constant of proportionality relating the energy of a photon to its frequency, now defined as exactly 6.62607015 x 10^-34 Joule-seconds (J s)
   - Planck's constant, Planck constant

1. (thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure
   - heat content, total heat, enthalpy
    
2. A nonmetallic univalent element that is normally a colourless and odourless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe
   - hydrogen, atomic number 1
    
3. 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
   "Large inductors used in power supplies are often rated in Hs";
   - henry

Derived forms: hs, Hs

Type of: alphabetic character, chemical element, constant of proportionality, element, factor of proportionality, gas, inductance unit, letter, letter of the alphabet, physical property

Part of: H2O, Latin alphabet, Roman alphabet, water

Encyclopedia: H