Question

The structure of solids is investigated by using:

• A. Cosmic rays
• B. \( \beta \)-rays
• C. X-rays
• D. \( \gamma \)-rays

Hint:

X-ray diffraction (XRD) is used to study crystal structures and material properties.

Answer 1

The Correct Option is C

The investigation of solid structures is primarily conducted using X-rays. This technique is based on the principles of X-ray crystallography, which involves the diffraction of X-rays by the tightly packed atoms within a crystal lattice. When X-rays are directed onto a crystalline solid, they are scattered in various directions. By analyzing these scattered rays, one can infer the electron density within the crystal structure, allowing scientists to deduce the positions of the atoms.

Why X-rays? X-rays are particularly suitable for this purpose due to their wavelength, which is on the same order of magnitude as the distances between atoms in a solid. This allows them to interact with the crystal lattice and produce a diffraction pattern that can be analyzed to determine the atomic structure.

In contrast, cosmic rays, \( \beta \)-rays, and \( \gamma \)-rays are not typically used for investigating solid structures:

• Cosmic rays: These high-energy particles originate from outer space and do not have the appropriate wavelength or properties for detailed structural analysis of solids.
• \( \beta \)-rays: Composed of high-energy, high-speed electrons or positrons, \( \beta \)-rays are more applied in other areas like radiation therapy and not suitable for crystallography.
• \( \gamma \)-rays: While they have smaller wavelengths than X-rays, they are too energetic. The interaction with matter tends to be more about particle interactions rather than wave-like interactions required for diffraction studies.

Thus, X-rays are the preferred and most effective method for investigating the structure of solids.

Answer 2

Option	Investigation Use
Cosmic rays	Not typically used for investigating the structure of solids; primarily studied for understanding high-energy particles from space.
\( \beta \)-rays	Not used for structural analysis of solids; these are electrons emitted by certain types of radioactive decay.
X-rays	Used for investigating the structure of solids through techniques like X-ray crystallography, which provides detailed information about crystal structures.
\( \gamma \)-rays	Used less frequently for structural analysis, mainly applied in studying nuclear processes and materials.

The correct method for investigating the structure of solids is using X-rays. X-ray crystallography is a powerful tool allowing scientists to determine the atomic and molecular structure of a crystal. In this technique, X-rays are directed at the crystal and diffracted into many specific directions. By measuring the angles and intensities of these diffracted beams, a three-dimensional picture of the electron density within the crystal can be generated. This electron density map can then be used to determine the positions of the atoms in the crystal, as well as their binding interactions, thus revealing the structure of the solid.