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
Answer:
C
Explanation:
Protozoa have been classified into three trophic categories: the photoautotrophs which harness the sun's radiant energy in the process of photosynthesis; the photoheterotrophs, which although phototrophic in energy requirements, are unable to use carbon dioxide for cell synthesis and must have organic carbon compounds
Answer:
A circle is a closed curved shape that is flat. ... Instead of having all points the same distance from the center point, though, an ellipse is shaped so that when you add together the distances from two points inside the ellipse (called the foci) they always add up to the same number.
Explanation:
True
because ur hart pumps faster and then blood flow increases and the you have more blood delivery to your body