The characterstics X-ray spectrum is emitted due to transition of

Options

A. valence electrons of the atom
B. inner electrons of the atom
C. nucleus of the atom
D. both, the inner electrons and the nucleus of the atom

Answer

To solve the question regarding the emission of characteristic X-ray spectrum, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Characteristic X-rays**: Characteristic X-rays are produced when an electron from a higher energy level falls into a lower energy level (or shell) after an inner shell electron has been ejected.

2. **Electron Bombardment**: When high-energy electrons bombard a target material (usually a metal), they can impart enough energy to eject inner shell electrons (for example, from the K shell).

3. **Creation of a Vacancy**: The ejection of an inner shell electron creates a vacancy in that shell. For instance, if an electron is ejected from the K shell, there is now a vacancy in the K shell.

4. **Transition of Electrons**: Electrons from higher energy levels (like L, M, or N shells) can transition down to fill this vacancy. When an electron from a higher shell (say L shell) falls into the K shell to fill the vacancy, it releases energy.

5. **Emission of X-rays**: The energy released during this transition is emitted in the form of X-rays. This emission is what we refer to as characteristic X-ray radiation because the energy (and thus the wavelength) of the emitted X-rays is characteristic of the element from which the X-rays are emitted.

6. **X-ray Series**: Depending on which inner shell electron is ejected and which higher shell electron fills the vacancy, different series of X-rays can be produced, such as the K series, L series, and M series.

7. **Conclusion**: Therefore, the characteristic X-ray spectrum is emitted due to the transition of electrons from higher energy levels to fill vacancies created by the ejection of inner shell electrons.

### Final Answer:
The characteristic X-ray spectrum is emitted due to the transition of electrons from higher energy levels to lower energy levels (specifically filling vacancies left by ejected inner shell electrons).

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