The science of chemistry is divided into two divisions: the chemistry of life or organic chemistry and the chemistry of everything non living or inorganic .  Organic means containing carbon.  It turns out that carbon is the only element on which life can be based.  So carbon is indeed a very special element.  

The nucleus of an atom of carbon 12 has six protons and six neutrons and is formed when three alpha particles become one nucleus.  An alpha particle is just the nucleus of a helium atom which is composed of two protons and two neutrons.  Scientists have scratched their heads over how carbon is actually created.  When two alpha particles come together, they form an unstable nucleus which would immediately break up; so the hope of getting three together at the same time would seem an impossible task.  However, surprisingly they do.  So the reasoning is that three alpha particles have somehow an attraction for each other.  This mutual pull means that three alpha particles will get fairly close to each other.   In this close proximity they can then merge into the carbon nucleus. 

On the other hand, this means if the nucleus of a carbon atom were excited by shooting another particle at it with just the right amount of energy, it would decompose into three alpha particles which because of the attraction would still hang together albeit loosely.  In time the alpha particles would come back together as a carbon nucleus releasing a gamma ray.  This scenario has been tested and affirmed.  It could also happen that while the carbon nucleus is in this excited state and with enough added energy, the three alpha particles of the original carbon nucleus can fly apart permanently.  So in a three stage process the three alpha particles can be merged into a carbon nucleus, or hang together loosely in a state of mutual attraction (excited state of carbon) or they can disassociate into three separate alpha particles.

Ref: Gravity From the Ground Up by Bernard F Schutz, p133