energy and society

Question

State whether each of the following statements describes alpha particles, beta particles, or gamma radiation: (6 marks)

a) The largest of the three.

b) The most penetrating of the three.

c) Of the three, they are the slowest moving.

d) Like electrons, they have a negative charge.

e) They are very strongly ionizing.

f) They travel at the speed of light and have no mass. 

Answer 1

a) Alpha particles. as they are helium nuclei.

b) Gamma radiation as these are EM waves with extremely small wavelengths.

c) Alpha particles as they are the most massive and ionizing ones.

d) Beta particles as they have a negative -1 charge.

e) Alpha particles as they are +2 charge ionize the most.

f) Gamma radiation they are EM waves therefore travel at the speed of light.

Answer 2

An alpha particle is an ion of Helium, consisting of two protons, and two neutrons.

A beta particle is an electron or a positron resulting from beta decay.

Gamma radiation is electromagnetic radiation with frequency above 3×10¹⁹ Hz.

a) Alpha particles have the largest mass of the three.

If the word largest" really refers to physical dimension, then that

is not so well defined, but by any measure the alpha particle would also be the largest.

b) Gamma radiation is the most penetrating.

c) Alpha particles are the slowest.

d) Alpha particles always have positive charge.

Gamma radiation never has any charge.

Beta particles can be electrons or positrons.

I do not like the question, but the only possible answer is that

beta particles are the only ones that sometimes have negative charge.

(Actually they often do.)

e) Both beta and gamma particles are strongly ionizing.

Where beta particles can reach, they can be more ionizing that gamma radiation.

But gamma radiation can penetrate deeper, and therefore normally causes

grater ionizing damage to human tissue.

f) Only gamma radiation is a candidate.

But it would be more accurate to say that gamma particles have no REST mass.