Fusion reactions constitute the fundamental energy source of stars, including the sun. hydrogen “burning” initiates the fusion energy source of stars and leads to the formation of helium. generation of fusion energy for practical use also relies on fusion reactions between the lightest elements that burn to form helium. in fact, the heavy isotopes of hydrogen—deuterium and tritium—react more efficiently with each other, and, when they do undergo fusion, they yield more energy per reaction than do two hydrogen nuclei. the hydrogen nucleus consists of a single proton. the deuterium nucleus has one proton and one neutron, while tritium has one proton and two neutrons. what conclusion can be drawn from this information? a) deuterium and tritium are required to burn hydrogen. b) the most efficient fusion reactors would use two hydrogen nuclei. c) the most efficient fusion reactors would use heavier forms of hydrogen. d) helium occurs naturally. the burning of hydrogen is not required to get helium in nature.

C)  The most efficient fusion reactors would use heavier forms of hydrogen.

Explanation:

From the information presented to us in the question, the third sentence reveals that heavier forms of hydrogen produces larger amount of energy and most importantly reacts more efficiently when fusion occurs.

In fact, the heavy isotopes of hydrogen—deuterium and tritium—react more efficiently with each other, and, when they do undergo fusion, they yield more energy per reaction than do two hydrogen nuclei.

the answer is:  

line graphs show patterns in data with variables that change over time; whereas, circle graphs show data as parts out of a whole (such as out of 100%).

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

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