Each member of the electron transport chain is lower in free than the preceding member of the chain, but higher in the molecule at zero free energy, which is is lowest of all the molecules in free energy and highest in electronegativity.

c. orbital shape i hope this is correct

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.