This Inquiry Learning Space aims at understanding the different types of radioactivity particles and the basics about radioactivity decay. Factors that influence the radioactivity intensity (distance from radioactivity source, exposure time and presence of absorbers) will also be discussed.
The Radioactivity Lab examines the intensity of radiation over distance, demonstrating the effects of the inverse square law. Students investigate the intensity of radiation being emitted from a radioactive Strontium-90 source, by setting distances at which a Geiger counter measures radiation, and collecting radioactive particle counts at each of these distances. A table holding the radioactive source is rotated until the source is aligned with a hole in a thick lead plate. The head holding the Geiger-Muller tube is moved to these distances from the radioactive source.
With this Inquiry Learning Space students will learn how exposure time, distance and absorbers affect the measurements of radiation.
In this Inquiry Learning Space students are able to conduct three different experiments:
Experiment 1: Keep everything constant and change only the distance
In this experiment students are able to verify how the distance from a radioactivity source impact the intensity of measured radiation. The measurements are carried out at four different distances (15mm, 20mm, 25mm and 35mm).
Experiment 2: Keep everything constant and change only the time
Experiment 2 students can verify how the time the Geiger counter is exposed to the radioactivity source influences the radioactivity measurements. They keep the distance constant at 20 mm and measure the radioactivity for 5, 10 and 15 seconds of exposure time.
Experiment 3: Keep everything constant and change only the Absorbers
In this experiment students are asked to keep distance and time constant and change the absorbers placed in between the radioactivity source and the Geiger counter. They measure the radiation for five different absorbers: None, paper, aluminium sheet, lead sheet, aluminium disc and lead disc.
A computer with internet connection is necessary.