Sauerstoff1816O

Sauerstoff1816O, commonly known as oxygen-18 or 18O, is a stable isotope of oxygen. It contains eight protons, eight neutrons, and eight electrons, giving it an atomic mass of approximately 18 atomic mass units. This isotope is one of the three naturally occurring isotopes of oxygen, the others being oxygen-16 (16O) and oxygen-17 (17O).

Oxygen-18 is less abundant than oxygen-16, making up about 0.204% of the total oxygen content on Earth. It is typically found in water molecules (H2O) and carbon dioxide (CO2) in the atmosphere. The ratio of oxygen-18 to oxygen-16 in water can vary depending on factors such as temperature, precipitation, and evaporation, making it a useful tool in studying past climates through the analysis of ice cores and other geological samples.

In the field of paleoclimatology, the ratio of oxygen-18 to oxygen-16 in ice cores is used to infer past temperatures. This is because the heavier oxygen-18 isotope is slightly more likely to condense and fall as precipitation at lower temperatures, while the lighter oxygen-16 isotope tends to remain in the atmosphere longer. By analyzing the isotopic composition of ice cores, scientists can reconstruct past temperature variations and gain insights into historical climate patterns.

Oxygen-18 is also used in various scientific and medical applications. In medicine, it is used in positron emission tomography (PET) scans, where it is incorporated into radiopharmaceuticals to track metabolic processes in the body. In research, it is used as a tracer in studies of biochemical pathways and metabolic processes. Additionally, oxygen-18 is used in the production of heavy water (D2O), which has applications in nuclear reactors and neutron moderation.