Elements heavier than hydrogen are formed when light elements undergo nuclear fusion. Fusion takes place within stars at tempera
tures nearing 108K. Explain why this high energy is required for fusion to occur. A) High temperatures result in high kinetic energy that is converted to the nuclear binding energy. B) High temperatures result in the high kinetic energy needed to overcome the repulsive force of the two nuclei. C) High temperatures result in high kinetic energy that in turn creates a strong electrostatic force between the two nuclei. D) High temperatures result in the high kinetic energy needed to produce the strong force required to hold the nuclei together.
B is the best answer. Once the particles are sufficiently close, the strong nuclear force becomes stronger than the Coulomb repulsion and they are pulled together. This results in bound particles that have a binding energy that can be retrieved of you can get the particles far enough away from one another after binding, but this requires large and unstable nuclei (beyond lead on the table) These elements are referred to as radioactive, because they are prone to decaying
Limiting factors are resources or other factors in the environment that can lower the population growth rate. Competition for resources like food and space cause the growth rate to stop increasing, so the population levels off. This flat upper line on a growth curve is the carrying capacity.
