text: In reduced units, the operator for this quantity for the hydrogen atom is often expressed as one over the radius minus one half del-squared.
full_question: In reduced units, the operator for this quantity for the hydrogen atom is often expressed as one over the radius minus one half del-squared. For a particle in a box, the average value of this quantity is the integral of psi-star times the Hamiltonian of psi, and is minimized at h squared over eight times the mass times the length squared. This quantity does not commute with time, in a common expression of the uncertainty principle. (*) Degeneracy occurs for two states where this quantity is the same. H psi equals this quantity times psi, according to the time-independent Schrodinger equation. For 10 points, name this quantity that is quantized by Planck's constant, and which is measured in electron-volts or Joules.
first_sentence: In reduced units, the operator for this quantity for the hydrogen atom is often expressed as one over the radius minus one half del-squared.
raw_answer: energy [or total energy; or E; or kinetic energy; or Hamiltonian until it is read]