Formation of Heavy Elements in the Beginning

During the formation of the heavy elements, the density inside a star has to be great enough to sustain (a)   for extended time periods.

Heavy elements were formed by fusion of lighter nuclei in the interior of stars.

This process is called (a)   .

There are many nuclear synthetic pathways or nuclear fusions to produce heavy elements. They are the following EXCEPT:

• Triple Alpha process

• Carbon Nitrogen Oxygen cycle

• Alpha Ladder

• Proton-Proton Chain

This process uses the Carbon atom as a catalyst to form more Helium atom.

This happens in larger or hotter main-sequence stars.

(a)  

This process involves the continues fusion of elements with Helium, until heavier elements are created all the way to iron.

(a)  

This is the reaction which involves the fusion of three Helium atoms (alpha particles).

This results in the formation of the Carbon atom.

(a)  

Why is it that elements heavier than iron cannot be formed through fusion?

• For the reaction to occur, tremendous amounts of energy are needed.

• Those elements are too heavy and massive amount of gravity is needed.

• Tremendous amounts of alpha particles energy are needed.

• Massive amounts of carbon atom are required for the reaction to occur.

Elements heavier than iron are formed in a (a)   , a massive explosion of a star.

In supernova, (a)   reaction takes place, leading to formation of heavy elements.

This process involves the rapid capture of neutrons by the atom.

This is responsible for the creation of approximately half the atomic nuclei heavier than iron.

• R-process

• S-process

• Supernova

• Nuclear fusion