What conclusions can be drawn about the existence of nitrogen-14 and nitrogen-15?

Nitrogen-14 and nitrogen-15 are isotopes of nitrogen, with nitrogen-14 being the most abundant at approximately 99.6% natural abundance. The presence of both isotopes is key in fields like isotope geochemistry, which rely on the differences in their atomic masses for various studies. The ratio of nitrogen-15 to nitrogen-14 in a sample can provide insights into processes such as biological nitrogen fixation and denitrification.