What type of radiation is the slowest moving?

Alpha particles are the slowest moving type of radiation among the given options. These particles consist of two protons and two neutrons, making them relatively large and heavy compared to other forms of radiation. As a result, they have a lower velocity and cannot penetrate materials as effectively as gamma rays, beta particles, or x-rays.

Alpha particles travel at approximately one-tenth the speed of light, which is significantly slower than gamma rays and x-rays, both of which move at the speed of light due to their electromagnetic nature. Beta particles, being electrons or positrons, are lighter than alpha particles and also travel faster than them. Because of their greater mass, alpha particles are easily absorbed by materials such as paper or skin, further illustrating their slower movement and limited penetration capability.

Understanding the characteristics of different types of radiation, including their mass, charge, and speed, is crucial in the field of radiation safety and mitigation.