Reactant A contains 85j of chemcal energy. Reactant B contains 87.9j of chemical energy. Product C contains 38.7j of chemical energy, if the reaction absorbs 104.3j of chemical energy must product D contain?

a electronegativity decreases beacuse the size of nucleus is bigger.

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.