Question

Select the correct statements among the following:
A. Slow neutrons can cause fission in \( \frac{235}{92}U \) more effectively than fast neutrons.
B. \( \alpha \)-rays are Helium nuclei.
C. \( \beta \)-rays are fast moving electrons or positrons.
D. \( \gamma \)-rays are electromagnetic radiations with wavelengths larger than X-rays.
Choose the answer from the options given below:

• A. A, B and C only
• B. A, B and D only
• C. A and B only
• D. C and D only

Answer 1

The Correct Option is A

The question asks us to identify the correct statements from the given options regarding nuclear physics and radiation types. Let's examine each statement one by one: 

1. Statement A: Slow neutrons can cause fission in \(\frac{235}{92}U\) more effectively than fast neutrons.
   • This statement is correct. Uranium-235 is more likely to undergo fission when it absorbs slow (thermal) neutrons compared to fast neutrons. This is a widely known principle in nuclear physics.
2. Statement B: \(\alpha\)-rays are Helium nuclei.
   • This statement is correct. Alpha particles are Helium nuclei, consisting of 2 protons and 2 neutrons. They are emitted during alpha decay in radioactive materials.
3. Statement C: \(\beta\)-rays are fast moving electrons or positrons.
   • This statement is correct. Beta rays consist of high-energy, high-speed electrons or positrons emitted by certain types of radioactive decay, specifically beta decay.
4. Statement D: \(\gamma\)-rays are electromagnetic radiations with wavelengths larger than X-rays.
   • This statement is incorrect. \(\gamma\)-rays have shorter wavelengths than X-rays and are a part of electromagnetic radiation spectrum emitted from the atomic nucleus.

Thus, the correct statements are A, B, and C. Therefore, the correct option is: A, B and C only.