What is the penetrating ability of alpha radiation?

Alpha radiation consists of helium nuclei, which are relatively heavy and carry a positive charge. Due to their mass and charge, alpha particles have a low penetrating ability compared to other forms of radiation. They can travel only a short distance in the air, typically around 1 to 2 inches, before they lose energy and come to a stop. This limited range is primarily because alpha particles interact readily with matter, leading to rapid energy loss.

In addition to their limited air travel distance, alpha particles are also stopped by materials as thin as a sheet of paper or the outer layer of human skin. This greatly restricts their ability to penetrate, thereby limiting their overall exposure risk at a distance. Therefore, the correct understanding of alpha radiation's penetrating ability is that it can travel approximately 1 inch in air, which highlights the need for appropriate shielding and safety measures when working with radioactive materials emitting alpha radiation.