A student writes a plan to obtain a value for the distance travelled in air by alpha
particles.
He plans to use an alpha particle source, a Geiger-Müller tube with a thin window and a
counter.
His diagram is shown below.
He writes the following plan
His teacher says that the plan needs more detail.
Add more detail to improve this plan, include one safety precaution he should take.
You may add to the diagram if you wish.
Sensible comment on safety e.g. Keep hands away from the source
Any FIVE from
Measure (and record) background (count rate)
Mark d on diagram
Source and counter in line
Use metre rule to measure d (may be from diagram)
Measure to the same points (on the tube and source) each time
Start with tube close to source (and increase d)
Zero counter and start clock
Measure count for the same time each time
Repeat readings and find mean
For 5 mm < d < 35 mm
Plot graph of count against d
Where count (rate) falls sharply/to background is distance
travelled in air
