Which form of nuclear radiation is extremely penetrating and can be only blocked by a block of lead that is several centimetres thick?

Understanding Nuclear Radiation

Nuclear radiation refers to the particles and energy emitted during the decay of an atomic nucleus. The three common forms of nuclear radiation are alpha particles, beta particles, and gamma rays, each with different penetrating abilities and protective measures.

Characteristics of Radiation Types

1. Alpha Particles: These are heavy particles consisting of two protons and two neutrons. They have very low penetration ability and can be stopped by a sheet of paper or even the outer layer of human skin.

2. Beta Particles: These are electrons or positrons that are emitted from a nucleus. Beta particles can penetrate further than alpha particles but can be stopped by plastic, glass, or a few millimeters of aluminum.

3. Gamma Rays: These are high-energy electromagnetic waves. Gamma radiation is extremely penetrating and can travel through most materials, including human tissue. It requires dense materials, such as several centimeters of lead or several meters of concrete, to effectively shield against it.

Conclusion

In summary, the form of nuclear radiation that is extremely penetrating and can only be blocked by a block of lead that is several centimeters thick is gamma rays.