Question

When the X-rays strike a sample then the X-rays of the same wavelength as the incident beam is re-emitted and this is known as____________

(a) Modified radiation

(b) Same radiation

(c) Coherent radiation

(d) Non coherent radiation

I had been asked this question during an interview.

This intriguing question originated from Sources of Background Radiation Fluorescence topic in section X-Ray Diffraction of Solid State Chemistry

Answer 1

Correct choice is (c) Coherent radiation

For explanation: When X-rays strike a sample two types of scattered rays are produced. In the first, the incident beam sets the electrons of the atoms into vibration, the X-rays of the same wavelength as the incident beam is re-emitted and are the characteristic diffracted radiation with which we are familiar. This is known as coherent, unmodified radiation.