True or false: Alpha, beta and gamma can penetrate different materials.

This is true, the different types of radiation can penetrate different materials. Alpha radiation is the least penetrating and can be stopped by paper or skin. Beta is can pass through more things but will be stopped by a thin sheet of metal such as aluminium. Gamma is the most penetrating kind of radiation you need thick sheets of lead or several meters of concrete to stop gamma radiation.

This is true!

All the different types of radiation have different properties, in this case we’ll talk about their penetrating power.

Gamma radiation penetrates the most since it is just a high energy photon, meaning it is uncharged and massless and therefore doesn’t interact with matter as much so can travel much further.

Beta radiation is a high energy electron (therefore negatively charged). The charge on an electron is -1 so it interacts with matter more than gamma due to it being attracted or repelled by different particles. It also has mass therefore is more likely to be intercepted by other particles.

Alpha radiation is both more massive (comprising 4 nucleons) and more charged (+2) so it is more likely to interact with matter and be stopped in its path so penetrates less.

Hope that helps!