Why can only light nuclei undergo fusion, not heavy nuclei?

[Jam Smith]

http://physics.stackexchange.com/qu...le-to-undergo-nuclear-fusion-not-heavy-nuclei

Can anyone please explain me - what is similar between
Nuclear fission & Nuclear fusion?
Why are only light nuclei able to undergo nuclear fusion, not heavy nuclei?
I am a newbie for this topic.

 

[mfb]

The thread you linked has a good answer. What is unclear?

 

[Jam Smith]

The thread you linked has a good answer. What is unclear?

I agree that link has good answers, but As I am a new for this topic I want to know the basic depth knowledge.

Such things like,
Why do fusion reaction and fission reaction both release energy and how?
How much energy is released in a fusion reaction?

 

[mfb]

That is explained in the linked thread.
The Wikipedia articles give good introductions as well.