The elements of which group in the periodic table absorb the most energy when gaining an electron?

the elements in group 18 or group 8 A or the noble gas group in the periodic table absorb the most energy.

Explanation:

The process of gaining energy or absorbing energy during gaining of electrons is the electron affinity property of the elements. As the behavior of elements having electron affinity is to release electron to attain stable state or to release excess energy. These elements will gain the most energy while gaining an electron. The most electron affinity elements present in the periodic table are in group 18 or group 8A. As the noble gases are elements with fully filled shells, they will attain the most energy on further addition of electron.

So the elements in group 18 or group 8 A or the noble gas group in the periodic table absorb the most energy.

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.