The following line of reasoning, from Sir Nevill Francis Mott (On Teaching Quantum Phenomena 6 ), is illustrative of this development of quantum theory. The observation that the specific heat of a fixed amount of a monatomic gas at a constant volume is itself constant, suggests that the specific heat of the gas is solely due to the kinetic energy of the atoms. Heating the system increases the atoms' kinetic energy, while not seemingly transferring energy to the internal movement of the constituent components of the atoms (e.g., electrons and the nucleus). From this, it can be assumed a minimal potential and kinetic 'ground state' of the atom, that is separated from the next allowed 'state' by a finite amount that is larger than kT (here k is the Boltzmann constant, while T is the temperature). This quantized nature is confirmed by scattering experiments wherein the scattered particles (electrons) either suffer no energy loss, or loss of a specific definite amount (i.e., enough to cause atomic ionization).