AAMC FL Practice Exam

What occurs when an electron transitions from a high energy state to a lower energy state?

1. An atom absorbs energy

2. An atom emits a photon

3. A photon is destroyed

4. An electron changes its charge

The correct answer is: An atom emits a photon

When an electron transitions from a high energy state to a lower energy state, it releases energy in the form of a photon. This phenomenon is rooted in the principles of quantum mechanics, where electrons occupy discrete energy levels within an atom. When an electron is at a higher energy level, it has absorbed energy, which can come from various sources, such as thermal energy or electromagnetic radiation. As it transitions to a lower energy state, the energy difference between these two states must be conserved. Hence, the electron releases this excess energy, which manifests as a photon. This emitted photon corresponds to a specific wavelength of light, dependent on the energy difference between the two states, according to the equation E = hf, where E is the energy of the photon, h is Planck's constant, and f is the frequency of the photon. The other options do not accurately describe the process. The absorption of energy is related to an electron moving from a lower energy state to a higher one, not the reverse. Photons are not destroyed; rather, they are emitted when energy is released. Lastly, the charge of an electron remains unchanged during this transition; only its energy state alters. Thus, the correct understanding of this process confirms that an atom emits a