Characteristic X-rays are produced due to

Options

A. Transfer to momentum in collision of electrons with target atomss
B. Transition of electron from higher to lower electrons orbits in an atom
C. Heating of the target
D. Transfer of energy in collision of electrons with atoms in the target.

Explanation

### Step-by-Step Solution:

1. **Understanding Characteristic X-rays**:
Characteristic X-rays are a specific type of X-ray radiation that is produced when an atom is bombarded with high-energy particles.

2. **Bombardment with High-Energy Particles**:
The high-energy particles can be photons, electrons, or ions. When these particles strike an atom, they can transfer enough energy to eject an electron from one of the inner shells of the atom.

3. **Ejection of Inner Shell Electrons**:
When a high-energy particle collides with a bound electron in the inner shell of an atom, it can impart enough energy to eject that electron from the atom. This process leaves behind a vacancy or "hole" in the inner shell.

4. **Creation of a Hole**:
The vacancy created by the ejected electron is referred to as a "hole." This hole represents a lower energy state in the atom.

5. **Transition of Outer Shell Electrons**:
Electrons from the outer shells of the atom will then transition down to fill this vacancy. When these outer shell electrons move to the lower energy state (inner shell), they release energy in the form of X-rays.

6. **Emission of X-rays**:
The energy emitted during this transition corresponds to the energy difference between the higher energy state (outer shell) and the lower energy state (inner shell). This emitted energy is quantized and manifests as characteristic X-rays.

7. **Element-Specific Frequencies**:
The characteristic X-rays produced are unique to each element, as the energy levels of the electrons in different elements vary. Thus, the frequencies of the emitted X-rays are specific to the element being bombarded.

### Final Answer:
Characteristic X-rays are produced due to the transition of electrons from higher to lower energy levels in an atom after an inner shell electron has been ejected by the bombardment of high-energy particles.

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