Suppose you wanted to make 100 grams of water. A. What is the molar mass of water (H2O)? B. How many moles of water are in 100 grams? C. How many moles of hydrogen will you need? D. How many moles of oxygen will you need? E. How many grams of hydrogen and oxygen will you need? Hydrogen - Oxygen - F. Is your answer reasonable? Why or why not?

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.