thorium-228
A scientist carefully handles a sample of thorium-228 in a secure laboratory.
Noun: A radioactive isotope of the chemical element thorium, characterized by having a mass number of 228. This means its atomic nucleus contains 90 protons (defining it as thorium) and 138 neutrons (228 total nucleons).
This term is used specifically in scientific contexts, particularly in nuclear physics, chemistry, and geology, to denote this specific atomic variant of thorium. * The decay chain of thorium-232 includes thorium-228 as one of its daughter products. * Researchers measured the concentration of thorium-228 in the soil sample to determine its age. * Thorium-228 has a half-life of approximately 1.9 years.
- In Radiometric Dating: is part of the thorium decay series and can be used in conjunction with other isotopes to date marine sediments and carbonate materials.
- In Nuclear Medicine: While less common than other isotopes, and its decay products have been studied for potential use in targeted alpha-particle therapy for cancer treatment.
- Radioisotope (n): The general category to which belongs.
- Thorium-232 (n): The most common, naturally occurring, and long-lived isotope of thorium, which decays into .
- Radiothorium (n): A historical name for .
- Decay product / Daughter product (n): A nuclide resulting from the radioactive decay of a parent nuclide; is a decay product of .
- Radioisotope of thorium (mass 228): A descriptive synonym.
- ²²⁸Th: The standard scientific notation for this isotope, where "Th" is the chemical symbol for thorium and "228" is the mass number written as a superscript prefix.
- Thorium decay series: The sequence of radioactive decays beginning with and proceeding through isotopes including .
- Mass number: The total number of protons and neutrons in an atomic nucleus (e.g., the "228" in ).
A scientist carefully handles a sample of thorium-228 in a secure laboratory.
- radioactive isotope of thorium with mass number 228