Question 21

I picked answer A because I was thinking that alpha particle contains neutrons and it could cause U split chain reaction; ie. explosion. That's why you need to insulate the nuclear reactors. Does it make sense? Thanks.

[admin]

Very interesting perspective but it does not apply to this problem. After all, what you are really saying is that the lead and concrete is meant to protect the environment from a nuclear explosion as opposed to protecting the environment from alpha particles (which is an important distinguishing point).

Nonetheless, let's consider your reasoning. An alpha particle is a Helium nucleus which, of course, includes protons and neutrons. A U split chain reaction, which is beyond the scope of the MCAT, when one nuclear reaction releases single neutrons which in turn creates more nuclear reactions in an exponential manner.

In the end, this is a classic MCAT question which has been asked at least 20 different ways on the MCAT over the years in an attempt to see if you understand the following: alpha particle is charged with mass, beta particle is charged with mass, gamma particle is EM radiation thus no charge and no mass.