Final answer:
The minimum quantity of energy that can be gained or lost by an atom is known as the Quantum of Energy, which is fundamental in quantum physics, and is described by the equation E = hv where h is Planck's constant.
Step-by-step explanation:
The minimum quantity of energy that can either be lost or gained by an atom is known as the Quantum of Energy. In the realm of physics, this concept is fundamental to the understanding of how atoms interact with energy. The idea is that energy is not continuous but instead comes in discrete packets called quanta, which is the plural of quantum.
One of the key figures in the development of quantum theory was Max Planck, who proposed the idea that the energy of the photons is quantized and can be described using the equation E = hv, where E represents the energy of a photon, h is Planck's constant (which is approximately 6.626 × 10-34 J.s), and v is the frequency of the radiation. This understanding underpins many quantum phenomena, including the photoelectric effect observed by Albert Einstein, where photons transfer their energy to electrons, and it's on an "all or nothing" basis. Therefore, the correct answer to the question is D) Quantum of Energy.