Explanation:
When two small nuclei combine together to form a large nuclei then it is known as nuclear fusion.
When nuclei of two hydrogen atoms fuse together then it results in the formation of a helium atom along with the release of lot of energy. This energy is nuclear energy.
This nuclear reaction is as follows.

Thus, we can conclude that nuclear fusion represents nuclear energy.
Explanation:
1 kJ = 238.85 cal and
1 cal = 0.004187 kJ
so it will be 78.9×238.85 = <em><u>1</u></em><em><u>8</u></em><em><u>,</u></em><em><u>8</u></em><em><u>4</u></em><em><u>4</u></em><em> </em>calories
78.9 Kilojoules (kJ) = 18,844 Calories (IT) (cal)
Answer:
D: chain of volcanoes circling the Pacific Basin
Explanation: