Lu176

Lu176, or Lutetium-176, is a long-lived radioactive isotope of the element lutetium (atomic number 71) with a mass number of 176. It contains 71 protons and 105 neutrons. In nature, lutetium consists mainly of two isotopes: Lu-175, which is stable, and Lu-176, which is radioactive and present in small but detectable quantities. Lu-176 accounts for about 2.6% of natural lutetium.

Decay and half-life: Lu-176 decays by beta minus emission to Hafnium-176 (Hf-176). It has a half-life of approximately 37.6 billion years, making it one of the long-lived primordial radioisotopes. On geological timescales, its abundance changes very slowly, allowing Lu-176 to persist alongside Lu-175 since the formation of the Solar System.

Applications and significance: The decay of Lu-176 to Hf-176 underpins the Lu–Hf isotopic dating system, used in geochronology and planetary science. By measuring Lu-176 and its daughter Hf-176 in rocks and minerals, researchers infer crystallization ages and study the evolution of hafnium reservoirs in Earth's crust and mantle, providing insights into geological differentiation and the history of planetary bodies.

Occurrence: Lu-176 occurs naturally in trace amounts within lutetium-bearing minerals such as monazite and xenotime. Its presence, together with Lu-175, enables Lu-Hf dating to be applied to a range of geological materials.