Design Experiment: Investigate Alpha Particle Range in Air

[Faizi]

hello.
i will be appearing for my a levs in a couple of months and this is a 'design experiment' question i need help with. i haven't ever designed an experiment and help will be appreciated.

Question:

'Alpha particles from a particular radioactive source have a range of about 6 or 7 cm. This is because the kinetic energy of the alpha particles is continually being transferred to air molecules due to collisions between the alpha particles and air molecules.
Design a laboratory experiment to investigate how the range of alpha particles in air is affected by the air pressure. In your account it is expected that you will:

a) Draw a diagram showing how the apparatus would be used in your investigation (.. i suppose this won't be possible here...)

b) Explain clearly the procedure to be followed

c) name the alpha particle detector which you would use.

d) state any safety precautions which may need to be taken when performing this experiment

 

[member 553083]

.Answer:The experimental apparatus would consist of a radioactive source, a vacuum chamber, an alpha particle detector, and a pressure gauge to measure the air pressure in the chamber. The diagram below shows the arrangement of the apparatus.Diagram: [insert image]The procedure for the experiment would be as follows:1. Place the radioactive source in the vacuum chamber.2. Close the chamber and measure the air pressure in it using the pressure gauge.3. Turn on the alpha particle detector and measure the range of alpha particles from the source.4. Reduce the air pressure in the chamber by gradually opening a valve.5. Measure the range of alpha particles again and record the results.6. Repeat steps 4 and 5 until the desired pressure range is reached.The alpha particle detector that could be used in this experiment is a Geiger counter. Safety precautions that should be taken include:1. Wearing protective clothing to prevent exposure to radiation.2. Keeping the radioactive source away from any other objects or people.3. Making sure the vacuum chamber is securely sealed before proceeding with the experiment.4. Ensuring that the chamber is vented properly after the experiment is completed.

 

[thepatientmental]

First of all, congratulations on taking on the challenge of designing an experiment! It can be a daunting task, but with some guidance, you will be able to create a well-designed and informative experiment.

a) Unfortunately, I am unable to provide a diagram in this platform, but I can describe the setup of the experiment. You will need a radioactive source that emits alpha particles, such as radium or polonium, an alpha particle detector, a vacuum pump, and a pressure gauge. The detector should be placed at a fixed distance from the source, and the vacuum pump should be connected to a chamber that contains the source and the detector. The pressure gauge should also be connected to the chamber to measure the air pressure.

b) The procedure for this experiment would be as follows:

1. Set up the apparatus as described above.
2. Start the vacuum pump to create a vacuum inside the chamber.
3. Record the pressure reading on the gauge.
4. Turn on the radioactive source and record the reading on the alpha particle detector.
5. Slowly increase the air pressure inside the chamber by gradually releasing the vacuum.
6. Record the pressure readings and the corresponding alpha particle detection readings at different pressure levels.
7. Repeat the experiment multiple times to ensure accuracy and reliability of the results.
8. Analyze the data and plot a graph of alpha particle range vs air pressure.

c) The alpha particle detector that can be used for this experiment is a Geiger-Muller counter. This detector works by detecting the ionizing radiation produced by the alpha particles.

d) Safety precautions that need to be taken for this experiment include handling the radioactive source with caution, wearing protective gear such as gloves and lab coat, and ensuring proper ventilation in the lab. It is also important to follow proper disposal procedures for the radioactive source and any contaminated materials.

I hope this helps you in designing your experiment. Good luck with your A Levels!