Scientists call these different variations of the same element isotopes of each other. Radioactive refers to the characteristic that these isotopes are unstable and tend to fall apart.
For example, the element potassium (which always has 19 protons in its nucleus) occurs in nature in three forms: an isotope with 39 nucleons (19 protons and 20 neutrons), one with 40 nucleons (19 protons and 21 neutrons), and one with 41 nucleons (19 protons and 22 neutrons) . They emit, or radiate, particles in their conversion to stability. Isotopes exhibit a range of radioactive decay processes.
Specifically, by dividing the number of parent isotopes currently left in the sample ( Is this radioactive decay formula intimidating?
If so, try not to worry: This science project will only use its graphical representation, known as the decay curve .
It is now time to explore why geologists are so interested in these radioactive decay processes as a means of dating objects. This example might help clarify the processes and terms just introduced: Looking at the parent isotope potassium-40 (abbreviated as K-40) that decays into the daughter isotope argon-40 (abbreviated as Ar-40), scientists measured the half-life time to be 1.25 billion years.