Gamma rays are produced when?

Step 1: Analyze the question We need to identify the origin of gamma rays among the four options.

Step 2: Explain the concept Different electromagnetic radiations come from different processes:

• X-rays are produced when high-speed electrons are suddenly stopped by a metal target (bremsstrahlung), or when inner-shell electrons change energy levels.
• Ultraviolet, visible and infrared light come from changes in the energy levels of the outer electrons of atoms.
• Gamma rays come from the nucleus. After radioactive decay (alpha or beta), the daughter nucleus is often left in an excited state. When it drops to a lower energy state, it emits a high-energy photon, which is a gamma ray.

Step 3: Check each option

• A. This describes X-ray production, so it is wrong.
• B. Energy changes within the nucleus produce gamma rays, so this is correct.
• C. Energy changes in the electronic structure produce UV, visible light or X-rays, so it is wrong.
• D. Deflection of electrons in magnetic fields produces synchrotron radiation, not gamma rays in this context, so it is wrong.

Step 4: Answer

Exam tip: Remember "Gamma = Nucleus". X-rays involve electrons (stopping or inner shells), while gamma rays involve the nucleus. Whenever you see "nuclear energy level change" or "de-excitation of the nucleus", think gamma.