Measuring the half-life of ²¹⁵Po by low-level liquid scintillation counting

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.

Radioactive Decay As A Measure Of AgeAtoms of the same element always have the same number of protons, but the number of neutrons can vary. Atoms of the same element with different numbers of neutrons are called isotopes.For example, carbon has three common isotopes:Carbon-12 (6 protons, 6 neutrons)Carbon-13 (6 protons, 7 neutrons)Carbon-14 (6 protons, 8 neutrons)While carbon-12 and carbon-13 are stable, carbon-14 is unstable and undergoes radioactive decay, transforming into a different...

The half-life of a reaction (t1/2) is the time required for one-half of a given amount of reactant to be consumed. In each succeeding half-life, half of the remaining concentration of the reactant is consumed. For example, during the decomposition of hydrogen peroxide, during the first half-life (from 0.00 hours to 6.00 hours), the concentration of H2O2 decreases from 1.000 M to 0.500 M. During the second half-life (from 6.00 hours to 12.00 hours), the concentration decreases from 0.500 M to...

Radiometric DatingRadiometric dating is a scientific method used to determine the age of rocks, fossils, and ancient materials by measuring the decay of radioactive isotopes. Isotopes are atoms of the same element with different numbers of neutrons. Some isotopes are unstable and undergo radioactive decay, transforming into a different element over time. This transformation occurs at a predictable rate, known as a half-life, which is the time it takes for half of a radioactive substance to...

Protons and neutrons, collectively called nucleons, are packed together tightly in a nucleus. With a radius of about 10−15 meters, a nucleus is quite small compared to the radius of the entire atom, which is about 10−10 meters. Nuclei are extremely dense compared to bulk matter, averaging 1.8 × 1014 grams per cubic centimeter. If the earth’s density were equal to the average nuclear density, the earth’s radius would be only about 200 meters.
To hold positively charged protons together...

Positron Emission Tomography (PET) is a medical imaging technique that provides crucial insights into the body's physiological functions at a molecular level. It is an indispensable resource for diagnosing, staging, and monitoring various illnesses, notably cancer, neurological disorders, and cardiovascular conditions.
Fundamental Principles of PET