Magnesium oxide (mgo) has the rock salt crystal structure and a density of 3.58 g/cm3. the atomic weights of magnesium and oxygen are 24.31 g/mol and 16.00 g/mol, respectively. (a) determine the unit cell edge length.

i believe the answer is a.

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.