Radioactive Decay Law Calculator

The Radioactive Decay Law, fundamental to Nuclear Physics and Chemistry, helps us understand the rate at which radioactive nuclei decay over time. In this tutorial, we will delve into the calculations involved in determining the remaining number of nuclei of a radioactive species after a certain period, given its initial population and the decay constant.

Number of Nuclei Present in the Time by Radioactive Decay Law Calculator
Radioactive Decay Law Calculator Results
Number of Nuclei (N) = ρ

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Example Formula

The formula used to calculate the remaining number of radioactive nuclei based on the Radioactive Decay Law is:

N = N0 × e-λt
  1. N: This represents the number of remaining radioactive nuclei after time 't'.
  2. N0: This is the initial population of the radioactive species.
  3. λ: This is the decay constant of the radioactive species, characteristic of the species and indicative of its rate of decay.
  4. t: This is the time elapsed.

Who wrote/refined the formula

This formula is based on the fundamental principles of nuclear decay, first theoretically described by Ernest Rutherford in the early 20th century. The field of nuclear physics and our understanding of radioactive decay has since evolved, with this formula serving as a cornerstone. This principle is not only relevant to physics and chemistry but also has applications in geology (radiometric dating), medicine (radioactive tracers), and archaeology (carbon dating).

Real Life Application

In real life, this formula is crucial in the field of radiometric dating, where it is used to determine the age of rocks and fossils based on the decay of radioactive isotopes contained within them. Similarly, it is used in medicine for calculating the dosage of radioactive tracers used in diagnostic imaging.

Key individuals in the discipline

Ernest Rutherford, the father of nuclear physics, is the key individual in this field. His work in the early 20th century laid the groundwork for our understanding of atomic structure and radioactive decay, leading to the formulation of the Radioactive Decay Law. His contributions were recognized with a Nobel Prize in Chemistry in 1908.

Interesting Facts

  1. The Radioactive Decay Law has transformed our ability to understand the history of our planet. Radiometric dating, which is based on this principle, has been instrumental in dating ancient rocks and fossils, significantly advancing the field of geology.
  2. The field of medicine has been revolutionized by the application of the Radioactive Decay Law in nuclear medicine. Radioactive tracers, whose decay can be calculated using this law, are used in various diagnostic imaging techniques.
  3. The development of nuclear power, a significant source of our energy supply, is based on our understanding of radioactive decay and the principles outlined in this law.


The Radioactive Decay Law is a fundamental principle in Nuclear Physics and Chemistry, providing crucial insight into the behavior of radioactive species over time. Its applications, from radiometric dating to nuclear medicine, underline its significance and the importance of understanding the calculations and principles it involves.

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