The chemical equation below shows the combustion of propane (C3Ha). C3H8 +502 - 3C02 + 4H20
The molar mass of oxygen gas (O) is 32.00 g/mol. The molar mass of CzHg is 44.1 g/mol. What mass of O2, in grams,
is required to completely react with 0.025 g C3H8?

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.