Difference between exothermic chemical reaction and endothermic chemical reaction

Explanation:

exothermic reaction is a chemical reaction which involves the liberation of heat to the surroundings while endothermic reaction is a chemical reaction that involves the absorption of heat from the surroundings

answer is: nuclear fusion produces elements that are heavier than helium.

nuclei combine to form a heavier nucleus, releasing energy.  

for example, fusion of hydrogen atoms at the sun.  

this fusion nuclear reaction is in the inner core of the sun and hydrogen (atomic number 1) is conveted into helium (atomic number 2).  

the inner core is the central region of the sun and all solar energy is produced in the core by nuclear fusion.