Nuclear power is a nonrenewable energy resource. It is used to provide 20 percent of the electricity in the United States. How is nuclear energy harnessed to produce electricity, and what are two limitations of securing uranium?

Nuclear energy comes from splitting atoms in a reactor to heat water into steam, turn a turbine and generate electricity. Ninety-four nuclear reactors in 28 states generate nearly 20 percent of the nation's electricity, all without carbon emissions because reactors use uranium, not fossil fuels.

Explanation:

A nuclear reactor converts into electricity the heat produced by the fission of uranium nuclei. This electricity production can be adjusted according to demand. During normal operation, nuclear reactors are quite environmentally friendly, particularly with regard to greenhouse gases. Since the 1950s, reactors have evolved into “generations”, learning from the rare accidents to enhance their safety and robustness. Radioactive waste is produced in limited volumes, which allows for its containment in the very long term, but its management remains controversial.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.

the two answers are a, the population of birds with large beaks will increase on the island, and c, the trait for large beaks will be passed on to future generations through natural selection. the reason for that is because if the birds that have beaks developed for eating small seeds lose all of their food, they will go hungry and eventually starve because they physically cannot eat the large seeds, therefore making the population of large beaked birds higher. also, if the trait of large beaks are dominant on the island over small beaks, then over time the large beaked birds will reproduce more and more, while the smaller beaked birds will reproduce less and less because they can't survive with the food provided. that leads to the trait of small beaks disappearing and the trait of large beaks taking over the island.