Hi, I am Doctor Karl Slifer from the University of New Hampshire.
I perform research here at Jefferson Lab
Looking at the substructure of the proton 
And how the global properties of the proton 
arise from that substructure.
Another particle of interest is the neutron.
The neutron is very similar to the proton 
In that it has very similar mass - It has very similar properties
Except while the proton has a positive charge, 
The neutron is completely neutral, at least on a global scale.
If you dig deep enough into a neutron
It has a substructure 
And that substructure has patches of positive charge and negative charge.
On the whole
They all cancel out and you’re left with a net neutral object.
The proton and the neutron together 
Are the constituents, the basic constituents of the atomic nucleus
So the nucleus - If you look at any element in the periodic table
The nucleus of those elements
Are composed of a certain number of protons, a certain number of neutrons.
Certain configurations work
You can’t have just an arbitrary number.
But any element that you look at is going to be
The nucleus is going to be composed of these positively charged protons and the neutral neutrons.
