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:
Option-C
Explanation:
Scientists found a fossil of a fish with four limbs or legs. The fossil was estimated to be around 375 million years old.
The fossil showed the fins and scales of a fish but they also possess the bones of proto-wrist, shoulders and the elbow.
The presence of these bones can be a clue that the fish evolved the limbs to walk on the land and will later evolve into animals belonging to amphibians, reptiles and mammals. Therefore, the Tiktaalik is considered the missing link of how life evolved from water to land.
Thus, Option-C is correct.
Answer:
Solar flare
Explanation:
They are characterized by coronal mass ejections on the sun's surface. The ejected ionized particles if thrown in the direction of the earth will cause bright aurora as they colide with the earth’s ionosphere and magnetic field. These solar storms can also affect telecommunications satellites and also electricity grid systems.
Answer:
Because the organism is asymmetrical and it was able to regenerate, it’s probably (an amphibian), and belongs to the phylum (Mollusca).
