Question

Which of these types of radiation do you suppose we should fear the most if administered internally?

•Gamma rays
•Neutrons
•Alpha particles
•Beta particles
•Neutrinos
•X-rays

Answer 1

i think the answer is either Neutrons or Alpha particles

Answer 2

I guess the Alpha particles's energy will be completely released inside the body,

but some of the neutrons will exit the body without interaction.

it this right?

Answer 3

surely a neutron interaction will have more potential for dammage than an alpha particle though, because a neutron could cause a fission which could release lots of further radioactive decays.

Answer 4

On second thoughts; the nuclei that are most likely to become unstable from absorbing a neutron are not likely to be found in significant concentrations in a living body.

Answer 5

Actually i think most of the neutrons will leave the body without interaction because they are moving very to fast to be captured by nucleus

Answer 6

who said anything about the speed of the neutrons?

alpha particles are the most damaging, but they have very little penetrating power — a piece of tape or a layer of skin is enough to stop them. the problem is when an alpha emitter (such as the polonium-210 apparently used to kill Alexander Litvinenko) is ingested...

Answer 7

Alpha is a definite. While it doesn't have much penetrating power, they have extreme polarizability and hence a high probability of causing absorption or a change in nuclei.

Answer 8

I wouldn't want to consume a gamma source like cobalt-60, either, mind you!

Answer 9

I am certainly not planning on performing the experiment.

Answer 10

chromosomal damage from alpha particles is apparently on average about 20x that of an equivalent dose of gamma or beta radiation

Answer 11

A similar question

The penetrating power of radiation in water is most significant for:

•Gamma rays
•Alpha particles
•Beta particles
•Neutrons

i put neutrons and was marked incorrect

i suppose it should have been gamma?

Answer 12

This is why im not heaps sure about the question at the top,

as a living body is often modeled by a volume water

Answer 13

well, penetrating power implies that there's little interaction with the material being penetrated, right? neutrinos have perhaps the greatest penetrating power, but they also don't interact with anything...

Answer 14

neutrons are slowed by water; that's part of the point of using it as a coolant and moderator. it also does a pretty job of blocking beta particles, though high energy beta particles will cause x-ray emission when slowed in water. for gamma radiation, heavier, denser elements are better, but the primary factor is getting as many nuclei in the way as possible.

Answer 15

Ok, thank you @whpalmer4