Quarks: The building blocks of atoms

We all know that atoms are made up of negatively charged electrons revolving around a positively charged nucleus made up of neutrons and protons. But are these protons, neutrons and electrons too made up of something? Or are they the fundamental and smallest units of the atom? Now before you try to answer that question, lets ponder on another equally relevant point...... How do you discover what the protons and neutrons are made up of if they are indeed not the smallest and fundamental units? How?............ Confused?......... Well try asking yourself this...... Suppose you wanted to find out what was inside you remote controlled car, or you wanted to find out how the land phone in your house worked....... What would you have done then? The answer is fairly obvious I assume......... You would most definitely open it.

Just like that scientists literally tore apart the neutrons and protons. The only difference was that the scientists didn't use screw drivers or spanners to take care of the job, instead they used high energy collisions. That is, they bombarded protons with highly accelerated charged particles to tear them apart and studied them (somewhat similar to what we do when some screw in the machine won't budge and we have to "bombard" the phone or camera with hammers and other household tools accelerated to highly critical rates..............). And when they did that, they observed the presence of tiny charged particles in the protons and neutrons. These constituent particles of protons and neutrons are named as Quarks.

Now, let me tell you some very interesting facts about quarks:

• One can never find a quark by itself (i.e. they are always found in certain combinations). This behaviour of theirs' is explained by Quantum Chromodynamics, about which we shall learn later.

• They are found to possess a charge of either +2/3 or -1/3 (Anti-quarks, about which we shall learn later, possess a charge of either -2/3 or +1/3).

• They always arrange themselves to form particles of integer charge. e.g. 0, 1, 2, 3, etc.

Quarks are of six types (in pairs):

1. Up - Down

2. Top- Bottom

3. Charmed - Strange

(These are all types of quarks, i.e. there are up quarks and down quarks which form the protons and neutrons)

The charges of the diff. types of quarks are as given below:

up +2/3

down -1/3

top +2/3

bottom -1/3

charmed +2/3

strange -1/3

The composite particles formed by the combination of quarks are called Hadrons. e.g. protons, neutrons etc.

Two up quarks and 1 down quark combine to form a proton.

i.e. 2/3 +2/3 - 1/3

or, 4/3 - 1/3

or, 3/3 = 1

Hence the +1 charge of the proton.

For the neutron, it is the opposite. Two down quarks and one up quark combine to form a particle of zero charge.

We shall discuss more about the other types of quarks and the other possible type of Hadron (a Meson) later.

Our Sincere thanks to Rooplata Mam, the Person who Made it all Possible (Thank You Mam)....

Thank You,

Thinkers