A mixture of reactants and products at equilibrium is subjected to a series of changes. Determine which changes affect the composition of the equilibrium mixture, but leave the value of the equilibrium constant KcKc unchanged, affect the value of the equilibrium constant KcKc, or affect neither the composition of the equilibrium mixture nor the value of the equilibrium constant KcKc.

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.