WHAT ARE PROTONS AND NEUTRONS MADE OF? (QUARKS)
We have said that atom is made of nucleus and electrons. Nucleus is made of protons and neutrons. However, is there something smaller than protons and neutrons?
Protons and neutrons are made of quarks. But, what are these ‘quarks’?
Quarks are the basic fundamental building-block particles. Together they are creating protons and neutrons, or in other words, a nucleus of atom.
There are 6 types of quarks: up, down, charm, strange, top and bottom.
For now we are only going to mention up and down quarks.
One proton is made of 2 up and 1 down quarks.
One neutron is made of 1 up and 2 down quarks.
P – 2 up, 1 down
N – 1 up, 2 down
Quarks also have an electrical charge. Up quark has a charge of 2/3. Down quark has a charge of (minus)-1/3.
P – 2 up, 1 down = 2/3+2/3-1/3=1 …so, we say that proton is positively charged.
N – 1 up, 2 down = 2/3-1/3-1/3=0 …so, neutrons don’t have any charge, they are neutral.
If you never before heard about quarks, then maybe all this is little bit confusing. But don’t worry, in the next post we will go through ‘Standard model’. That will clear some things up. For now, all that you need to remember is that there are particles which are building protons and neutrons. Those particles we call ‘quarks’.