42Ca

42Ca, also known as calcium-42, is a radioactive isotope of calcium with a half-life of approximately 127 days. It is produced through the decay of potassium-42, which is a stable isotope of potassium. Calcium-42 is significant in scientific research, particularly in the field of geochronology, where it is used to study the age of rocks and minerals. Its radioactive decay allows scientists to determine the age of samples by measuring the ratio of calcium-42 to its stable daughter isotope, argon-42. This technique is valuable for dating geological events and understanding the history of the Earth's crust. Additionally, calcium-42 is used in medical imaging and as a tracer in biological studies to track calcium movement within the body. Despite its usefulness, the short half-life of calcium-42 means that it is not commonly found in nature and must be produced artificially for research purposes.