Nuclear Decay: Alpha and Beta Particles
There are over 100 different types of atoms. Some of these atoms are very unstable.
Over time, the nucleus of an unstable atom will lose energy by emitting various
particles spontaneously. This process is called nuclear decay. There are different
types of nuclear decay, including alpha and beta decay. There are two different types
of beta decay: beta minus (β–) decay and beta plus (β+) decay. Some scientists refer
to beta minus decay simply as beta decay, for convenience. This activity only deals
with this type of beta decay.
In this activity, you will determine the differences in the charge and mass of alpha
and beta minus (β–) particles and how their emission affects atoms.
1. Alpha Particles
a. What is the mass number of an alpha particle?
b. What is the identity of an alpha particle?
c. What kind of charge does an alpha particle have?
2. Beta Particles
a. What is the mass number of the particle emitted from the nucleus
during beta minus (β–) decay?
b. What kind of charge does the particle emitted from the nucleus during
beta minus (β–) decay have?
c. What is another name for a beta minus (β–) particle?
3. Nuclear Decay
a. What happens in the nucleus of an atom when an alpha particle is
b. What happens in the nucleus of an atom when a beta particle is
4. The helium used to fill birthday balloons doesn’t come out of the air, but from
out of the ground. Some of the gas might escape from the ground into the
atmosphere, but the majority of it is trapped in Earth’s crust. Based on what
you have learned in today’s lab, give a reasonable explanation for the
presence of helium gas in Earth’s crust.
5. Why should it take significantly more energy to move a beam of alpha
particles than a beam of beta minus (β–) particles?
6. What daughter product is produced when thallium–206, an isotope of