Geiger counter

How does the exhibit work?

In this exhibit, there are two discs: one disc with radioactive or non-radioactive objects and one disc with materials that can block radioactive radiation.

You can slide a radioactive object under the Geiger counter as well as a material to see how much radioactive radiation it blocks.

What is the science behind it?

The objects in the cabinet, you and everything around you, all consist of tiny particles. We call these atoms. Usually, these atoms don’t change over time. Some atoms are special, though: they do change, and energy is released during that change. The release of energy is radioactivity.

There are three types of radioactivity:

• Alpha radiation: you can block this radiation with a piece of paper.

• Beta radiation: you can block this radiation with a layer of plexiglass or aluminium.

• Gamma radiation: you can block this radiation with a thick layer of lead.

Some of the objects in the cabinet have special atoms and are therefore radioactive. How can you find this out? By sliding them under the Geiger counter. This is a device that measures radioactivity. The more clicks per second you hear, the more radioactive the object. You can also read the number of clicks per second (cps) on the screen.g lood.

These are the objects and the type of radiation that is released:

• Ionisation smoke detector (2001): radioactive, alpha and gamma radiation

• Optical smoke detector (2022): non-radioactive

• The mineral cuprite with impurities: radioactive, alpha, beta and gamma radiation

• The mineral chrysoprase: non-radioactive

• Potassium salt: radioactive, beta and gamma radiation

We are all naturally exposed to radioactive radiation. There are radioactive atoms in the soil, in the air, in our food and even in our own bodies. But the level of radiation is very low, and it can’t do any harm. It only gets dangerous above a certain level.

With thanks to the Federal Agency for Nuclear Control (FANC) for the radioactive objects.

Radioactivity in our food

Did you know that bananas are radioactive? This is because of the potassium that is naturally present in the fruit.

But don’t worry: you can definitely still eat bananas. Your body already contains some potassium anyway. In fact, an adult is about 280 times more radioactive than a banana.

Radioactivity in cancer treatment

Radioactive radiation can be dangerous, but not always. Sometimes it actually helps us. Doctors these days use radioactive radiation to destroy cancer cells. Radioactivity has already helped millions of people.