Science Education News (SEN) Journal 2017 Volume 66 Number 4 December 2017 | Page 55

YEARS 7–12 IDEAS FOR THE CLASSROOM
A box full of radiation – a visual representation to encourage
deeper learning of radioactivity
By Andrew C. Eaton
Introduction
The Stage 6 Chemistry area of radioactivity, and, in particular,
the main types of ionising radiation emitted from nuclei, provides
both interest and headaches for students. Below is a technique
that has been developed to reinforce the main types of nuclear
radiation, but also to develop a deeper understanding of their
role in nuclear chemistry.
The stimulus
Nuclei too big Too many
neutrons
Too few neutrons Too much energy
The introduction begins with the teacher putting four boxes
arranged in a square on the board:

Extension: During this section it is common for students to ask
why these scenarios lead to nuclear instability, and this can be
used to delve into nuclear forces versus electrostatic forces in the
nucleus. It is also handy to discuss the Segre chart and nuclear
stability.
Connecting to Stage 5
At this stage, I ask the students to write under the box the
three types of nuclear radiation that they learned in Stage 5.
Depending on the recall of the students, I try to tease out more
than just alpha, beta and gamma, and try to get them to describe
the particle nature of alpha and beta.

The teacher then asks the class to consider that there are four
scenarios that lead to nuclei emitting radiation. The students
draw the box then, either individually or as groups, try to fill in
the four scenarios. Depending on the prior knowledge of the
students, the teacher may need to provide more stimuli, but the
ultimate aim of this part is to fill the boxes on the board as the
class discusses the possibilities. Generally speaking, I start with
the first box (nucleus too big), then jump to the fourth box (too
much energy), then I work to the second and third boxes (too
many and few neutrons respectively).
Alpha radiation
After establishing the three types, I ask the students to hypothesise
which radiation type goes in which box. Some students can find
this challenging, so, after they have guessed, sometimes I need
to give a bit of guidance. I then start the discussion with the alpha
radiation.
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SCIENCE EDUCATIONAL NEWS VOL 66 NO 4