X-rays are produced by:
Correct answer: C. Cu
- A. He
- B. H
- C. Cu
- D. Na
Explanation
X-ray photons are produced when electrons in the outermost shells of an atom drop to the inner shells. Hydrogen atoms do not emit X-rays because the electron energy levels are too closely spaced together to permit the emission of high-frequency radiation. Transitions of this kind are normally forbidden because the lower states are already filled. However, if an inner shell has a vacancy (an inner electron is missing, perhaps from being knocked away by a high-speed electron), an electron from one of the outer shells can drop in energy to fill the vacancy. Out of the given choices, only copper emits X-rays and is also used in X-ray tubes. Hence, it is the answer.
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About Atomic Spectra
Atoms emit or absorb light at specific wavelengths because electrons occupy quantized energy levels and change levels by absorbing or releasing photons. The topic covers emission and absorption spectra, spectral series, hydrogen’s line spectrum, energy-level transitions, and the relation between wavelength, frequency and photon energy.
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