The correct answer is: Alpha radiation has the lowest penetrating ability.
Alpha radiation is a type of ionizing radiation consisting of two protons and two neutrons bound together into a helium nucleus. It is emitted from the nuclei of some radioactive atoms, such as uranium-238 and thorium-234. Alpha particles are relatively large and have a positive charge, which means they are easily stopped by matter. They can be stopped by a sheet of paper or even the outer layer of skin.
Beta radiation is a type of ionizing radiation consisting of high-energy electrons or positrons. It is emitted from the nuclei of some radioactive atoms, such as potassium-40 and carbon-14. Beta particles are smaller than alpha particles and have a negative charge, which means they are not as easily stopped by matter. They can be stopped by a thin sheet of metal or a few centimeters of water.
Gamma radiation is a type of electromagnetic radiation with no mass or charge. It is emitted from the nuclei of some radioactive atoms, such as cobalt-60 and cesium-137. Gamma rays are the most penetrating type of ionizing radiation. They can be stopped by thick layers of lead or concrete.
In conclusion, alpha radiation has the lowest penetrating ability, followed by beta radiation, and then gamma radiation.