Question

If a radioactive sample has an activity of \(7.55 \times 10^{5} \mathrm{~Bq}\), how many disintegrations per second are occurring?

Short answer

The sample undergoes \(7.55 \times 10^{5}\) disintegrations per second.

Step-by-step solution

Understanding Activity

The activity of a radioactive sample is measured in becquerel (Bq), which is equivalent to the number of disintegrations per second. Therefore, when the activity is given, it directly represents the number of disintegrations happening per second.

Relating Activity to Disintegrations

Since the activity of our sample is given as \(7.55 \times 10^{5} \mathrm{~Bq}\), this means there are \(7.55 \times 10^{5}\) disintegrations occurring per second.

Key concepts

Becquerel

The unit of becquerel (Bq) is fundamental in understanding radioactive decay. Named after the French physicist Henri Becquerel, this unit measures the activity of a radioactive substance. It specifically quantifies the number of atomic nuclei disintegrating per second in a radioactive material.
For students, it's essential to grasp that when we express a value in becquerels, we are describing the rate at which radioactive transformations occur. In simpler terms, 1 becquerel indicates that one disintegration happens every second.
This unit is widely used in various fields such as nuclear medicine, environmental monitoring, and physics research, where precise activity measurements of radioactive substances are crucial.

Disintegration

Disintegration in the context of radioactivity refers to the process where unstable atomic nuclei lose energy by emitting radiation. This is a natural and spontaneous event where a parent nucleus transforms into a different configuration, often forming a stable or less unstable daughter nucleus.
During disintegration, different types of particles can be emitted, including:

• Alpha particles – helium nuclei that consist of two protons and two neutrons.
• Beta particles – electrons or positrons emitted during radioactive decay.
• Gamma rays – high-energy photons released from the nucleus.

Understanding disintegration is key to studying radioactive decay processes and helps in predicting how a radioactive sample changes over time. Each disintegration event is an opportunity to learn about the underlying decay series and reaction pathways involved.

Activity Measurement

In the world of radioactivity, measuring the activity of a sample is vital for understanding how quickly it is undergoing decay. "Activity" is the term used to describe the number of disintegrations occurring in a radioactive substance per unit time.
Activity measurement is essential for:

• Safety and regulatory compliance, to ensure radiation exposure remains within safe limits.
• Medical applications, where precise dosages of radioactive tracers or treatments are required.
• Scientific research, where knowing the activity helps estimate the age or rate of decay in materials.

To measure activity, tools like Geiger counters, scintillation detectors, and ionization chambers are used. Each instrument has its own sensitivity and specific application, making them suitable for various types of radioactive substances.