Answer: The least penetrating of the given radioactive emissions will be alpha particles.
Explanation:
There are 3 radioactive particles which are emitted during radioactive processes:
1. Alpha particles: These particles are emitted when a nuclei undergoes alpha decay process. These particles have low energy associated with them.
2. Beta particles: These particles are emitted when a nuclei undergoes beta decay process. These particles have higher energy than alpha particles.
3. Gamma radiations: These radiations are emitted when an unstable nuclei undergoes gamma ray emission process and gives an excess energy through a spontaneous electromagnetic process. These radiations have the highest energy of all the radioactive particles.
Penetrating power of the particles is directly proportional to the energy of the particles, therefore:
\(\text{Penetrating power}\propto \text{Energy of the particles}\)
More the energy of the particles, more will be the penetrating power and vice-versa.
Increasing order of penetrating power will be:
\(\text{Alpha particles}<\text{Beta particles}<\text{Gamma radiations}\)
Hence, alpha particles is the least penetrating among the following radioactive particles.
