M Prep | MCAT 2015 Question of the Day - Prep, Practice Questions, and More!

Q:

A radiactive source is placed at one end of a closed container. On the other end is a several-meter thick inert material. Various particles are expelled from the radioactive substance and the penetrance number, defined as the length the particle traverses across the inert material divided by the total length of the material. Which of the following particles would be expected to have the lowest penetrance number?

A

alpha particle

B

beta particle

C

gamma ray

D

positron emission particle