What is the Mass Ratio of Alpha Particles, Neutrons, and Gamma Rays?

[lingling]

Homework Statement

which of the following mass ration is ture?

Mass of alpha-particles: mass of neutrons : mass of gamma- rays
equal to

A. 4 : 1 : 0
B. 4 : 0 : 1
C. 1 : 1 : 1
D. 1 : 1 :0

Homework Equations

nil

The Attempt at a Solution

I thought it's D
but the correct answer is A.
I can't get it..

 

[rsk]

An alpha particle consists of 2 protons and 2 neutrons, which are of equal mass (well, very nearly, anyway).

 

[lingling]

wow... silly me.
Thank you!

 

[dextercioby]

Alpha particle (in the past aka "alpha radiation") is the common name for the helium nucleus.

Daniel.