Bremsstrahlung occurs when a beta particle is slowed by the nucleus; which statement is true?

Bremsstrahlung occurs when a beta particle is slowed by the nucleus; which statement is true?

• A. The attractive force of the positive nucleus slows the beta particle.
• B. Bremsstrahlung is unrelated to atomic number.
• C. Bremsstrahlung occurs only with gamma rays.
• D. Kinetic energy is transformed into x-ray.

Answer: (D)

Bremsstrahlung comes from a charged particle, like a beta electron, being slowed or deflected by the electric field of a nucleus. That deceleration causes the particle to emit radiation. The energy carried away by the emitted photon comes from the beta particle’s kinetic energy (with a bit of recoil energy transfer to the nucleus) so energy is conserved. In other words, kinetic energy of the particle is transformed into the energy of an x-ray photon. This explains why the statement about kinetic energy becoming x-ray energy is the best description. The other ideas are incomplete or misleading: the radiative process is due to the electromagnetic interaction with the nucleus (not just a vague “attractive force” wording), and bremsstrahlung strength grows with atomic number (it’s not independent of Z). Also, bremsstrahlung produces x-rays, not gamma rays, so it’s not limited to gamma emission.

Bremsstrahlung comes from a charged particle, like a beta electron, being slowed or deflected by the electric field of a nucleus. That deceleration causes the particle to emit radiation. The energy carried away by the emitted photon comes from the beta particle’s kinetic energy (with a bit of recoil energy transfer to the nucleus) so energy is conserved. In other words, kinetic energy of the particle is transformed into the energy of an x-ray photon.

This explains why the statement about kinetic energy becoming x-ray energy is the best description. The other ideas are incomplete or misleading: the radiative process is due to the electromagnetic interaction with the nucleus (not just a vague “attractive force” wording), and bremsstrahlung strength grows with atomic number (it’s not independent of Z). Also, bremsstrahlung produces x-rays, not gamma rays, so it’s not limited to gamma emission.