Six atoms of Element A combine with eight atoms of Element B to produce six compounds particles. How many atoms of Elements A and B does each particle contain? Are all of the atoms used to form compounds?

the answer is a

photosynthesis

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.