Electrolysis breaks down water to form hydrogen and oxygen gas. the word equation that represents this reaction is: water

When a reduction reaction and an Oxidation reaction takes place due to passing of current through water the molecules of water split into the compounds. Where it is made up of hydrogen in its state of gas and also Oxygen in its state of gas this method is most vastly is known as electrolysis.

In this process a certain direct current is passed from inside water. This direct current value can be near about 1.23 voltages the reaction that happens inside is given below.

           2 Water---> Oxygen + 4 hydrogen ions + 4 Electrons

            2 Hydrogen ions + 2 electrons > hydrogen gas  

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.