Analyzing Radioactive Decay and Half-Life Calculations

The video tutorial explains how to interpret a decay graph showing the count rate of a radioactive isotope over 10 days. It addresses why the count rate stops falling after 8 days, attributing it to background radiation. The tutorial emphasizes the importance of subtracting background radiation from data before calculating the half-life of the isotope. The half-life is determined to be approximately one hour after data correction. The video concludes with a reminder to always account for background radiation in radioactivity experiments.

What does the vertical axis represent in the decay graph?

• Time in days

• Count rate in counts per minute

• Background radiation

• Half-life

Why does the count rate appear to stop decreasing after 8 days?

• The isotope has reached a stable state

• The count rate is now only background radiation

• The detector is malfunctioning

• The isotope has completely decayed

What is the background radiation count in this experiment?

• 40 counts per minute

• 30 counts per minute

• 20 counts per minute

• 10 counts per minute

Why is it important to subtract background radiation in radioactivity experiments?

• To reduce the time of the experiment

• To increase the count rate

• To ensure accurate half-life calculations

• To avoid using complex equipment

What is the first step in adjusting the data for half-life calculation?

• Multiply the data by two

• Subtract background radiation from the data

• Add background radiation to the data

• Divide the data by the count rate

What is the initial count rate after subtracting the background radiation?

• 60 counts per minute

• 100 counts per minute

• 40 counts per minute

• 80 counts per minute

How long does it take for the count rate to decrease from 80 to 40 counts per minute?

• 3 hours

• 2 hours

• 1 hour

• 30 minutes

What is the half-life of the isotope based on the adjusted data?

• 30 minutes

• 1 hour

• 2 hours

• 3 hours

What would happen if you calculated the half-life without subtracting background radiation?

• The half-life would be longer

• The half-life would be shorter

• The half-life would remain the same

• The half-life calculation would be incorrect

What should you do if given data in a table or graph for half-life calculation?

• Multiply the data by the count rate

• Add the background radiation

• Subtract the background radiation

• Ignore the background radiation