QUARKS & GLUONS

The smallest particle in nature is the quark, which is the building block of protons and neutrons. Quarks are not found as isolated entities, but are always bound together within these particles. Quarks have a size of about 10^-18 meters, which is much smaller than the size of an atom.

There are also particles that are smaller than quarks, such as leptons (such as electrons), but they are considered point-like and have no size. They are considered to be the basic building blocks of matter and carry a unit of electric charge.

In addition to these fundamental particles, there are also composite particles, such as mesons and baryons, which are made up of quarks and/or antiquarks. These particles have a size, but it is much smaller than the size of an atom.

Overall, the smallest particle in nature is considered to be a point-like particle, such as a lepton, and there is no known particle that is smaller than this.

Are preons the smallest particles ever discovered?

No, preons are not considered the smallest particles ever discovered. Preons are hypothetical particles that were proposed as the building blocks of quarks and leptons, which are the basic building blocks of matter in the standard model of particle physics. However, there has been no experimental evidence to support the existence of preons, and current scientific understanding supports that quarks and leptons are the fundamental building blocks of matter. The smallest particles currently known are subatomic particles such as quarks, electrons, and neutrinos.

Explain why electrons are fundamental particles and protons and neutrons are not because they are made of other fundamental particles called quarks?

Electrons, protons, and neutrons are subatomic particles that make up atoms. Electrons are negatively charged particles that orbit the nucleus of an atom. Protons are positively charged particles that are found in the nucleus of an atom, and neutrons are uncharged particles that also reside in the nucleus.

Electrons are considered fundamental particles because they cannot be further broken down into smaller particles. This means that electrons are considered indivisible and cannot be divided into smaller components. In contrast, protons and neutrons are not considered fundamental particles because they can be broken down into smaller components, called quarks. Quarks are the building blocks of protons and neutrons, and they have fractional charges.

The concept of quarks was first introduced by physicists Murray Gell-Mann and George Zweig in 1964. They proposed that protons and neutrons were composed of three smaller particles, called quarks, which are held together by the strong force. This theory, known as the theory of quantum chromodynamics (QCD), has been confirmed by numerous experiments and is considered a cornerstone of modern particle physics.

In conclusion, electrons are considered fundamental particles because they are indivisible and cannot be broken down into smaller components, while protons and neutrons are not considered fundamental particles because they are made up of smaller building blocks, called quarks, which are held together by the strong force.