Which type of radiation is known to penetrate the least depth but poses the greatest cancer risk?

Alpha particles penetrate the least depth among the types of radiation mentioned. They are relatively heavy and charged particles, consisting of two protons and two neutrons. Because of their size and charge, alpha particles can be effectively stopped by a sheet of paper or even the outer layer of human skin. Despite their limited penetration ability, alpha particles pose a significant cancer risk when ingested or inhaled, as they can cause substantial damage to the sensitive internal tissues and cells due to their high mass and energy.

The biological impact of alpha radiation is much more profound when it comes into direct contact with living cells. The dense ionization produced by alpha particles in localized areas can lead to cellular damage, mutations, and an increased risk of cancer over time, especially in tissues that are sensitive to radiation.

In contrast, other forms of radiation such as beta particles, gamma rays, and neutron radiation are more penetrating. Beta particles can penetrate skin and can be harmful if they enter the body, while gamma rays can pass through the body and require dense materials like lead for effective shielding. Neutron radiation is even more penetrating and requires specific materials like hydrogen-rich substances for adequate shielding. Therefore, while alpha particles are not able to penetrate very deeply, their potential for causing significant biological harm