For 10 points—identify this type of energy, named after an American physicist.
Representing the change in energy of a system at constant temperature and constant pressure, thermodynamic systems will exhibit a spontaneous change only if this quantity decreases during the process. It can be calculated from the internal energy by adding the product of pressure and volume and subtracting the product of temperature and entropy. For 10 points—identify this type of energy, named after an American physicist.
Representing the change in energy of a system at constant temperature and constant pressure, thermodynamic systems will exhibit a spontaneous change only if this quantity decreases during the process.
{Gibbs} free {energy} [prompt on {free energy}]