Final answer:
The lighter isotope of oxygen, 16O, has 8 protons and 8 neutrons. Oxygen-16 is more abundant and lighter than oxygen-18, which has 8 protons and 10 neutrons. The relative abundance of these isotopes can be used in oxygen isotope analysis to understand past climatic temperature.
Step-by-step explanation:
The lighter isotope, 16O, has 8 protons and 8 neutrons. Oxygen-16 is the most common form of oxygen, while oxygen-18 is rarer and has 8 protons and 10 neutrons. Oxygen-16 is lighter than oxygen-18, which is why water molecules containing oxygen-16 are preferentially evaporated from the oceans compared to those containing oxygen-18. This has implications for oxygen isotope analysis, as the relative abundance of oxygen-16 and oxygen-18 can provide insights into climatic temperature at the time ice was deposited.