Oxygen-16 and Carbon-12 are stableisotopes of elements O and C respectively. Hence, they do not have half-lives. But Carbon-14 andUranium-238 are radioactive isotopes. Among them Carbon-14 has relatively short half-life as about 5730 years while Uranium-238 has a long half-life as about 4.5 billion years.
Answer is. uranium-238
It is Chemistry.
Cu+AgNO3=Ag+Cu(NO3)2
==>
Cu+2AgNO3=2Ag+Cu(NO3)2
An environment high in carbon dioxide and high in oxygen induce oxygen to bind to hemoglobin. Another factors are an environment under high pressure and an environment under low pressure.
Their purpose is reproduction.