Experiments show that protons and neutrons consist of smaller parts
which called quarks.
                       


A proton consist of 1 down quark and 2 up quarks.





  A neutron consists of 2 down quarks and 1 up quark.


  There are 6 types of quarks 




Quarks can only be "seen" during nuclear reactions. 




Proton
Netron
Up
Down
Charm
Strange 
Top
Bottom