What type of x-rays are emitted when an outer shell electron fills an inner shell vacancy?

• A. Bremsstrahlung x-rays
• B. Characteristic x-rays
• C. Continuous x-rays
• D. Soft x-rays

Answer: (B)

When an outer shell electron fills an inner shell vacancy, it results in the emission of characteristic x-rays. This process is known as electron transition, where an electron from a higher energy shell drops down to a lower energy shell (the inner shell) that has a vacancy. As the electron transitions to the lower energy level, it releases energy in the form of radiation, specifically x-rays, which are distinctive of the elemental material involved.

Characteristic x-rays are unique to the element because the energy released during this transition corresponds to the difference in energy levels of the electrons in that specific atom. This means that the energy (and thus the wavelength) of the emitted x-ray serves as a fingerprint for identifying the element from which they originated. This type of x-ray formation is crucial in various applications such as x-ray spectroscopy, which identifies the composition of materials.

In contrast, bremsstrahlung x-rays are produced when high-speed electrons are decelerated upon interaction with the nucleus of an atom, leading to a broader spectrum of energies rather than distinct, characteristic energy levels. Continuous x-rays are essentially another name for bremsstrahlung, emphasizing the continuous nature of the spectrum emitted. Soft x-rays refer to x-rays with lower energy and longer wavelengths, which are