The discovery of the proton occurred in 1815 when the British chemist Willian Prout revealed that all atoms
are composed of hydrogen atoms or commonly called protyles. The channel rays or ions which have
a positive charge and are formed from gases were discovered by a German physicist, Eugen Goldstein in 1886.
He observed that the ratio of charge to mass of hydrogen ions was the highest among all gases.
In addition, Goldstein also observed that hydrogen ions have the smallest size among all ionized
The atomic nucleus was discovered by Ernest Rutherford in 1911 during his research on his famous gold foil.
He concluded that all particles have a positive charge inside the atom which is concentrated in a
single nucleus and most of the volume inside the atom is empty. Rutherford also discovered that
the total number of positively charged particles in the nucleus equals the total number of negatively
charged electrons surrounding it.
History of Proton Discovery and Proton Discovery
If the maa of electrons is 0, then a particle will have no mass. However, in reality,
particles of matter have a mass that can be measured, and these atoms are neutral. How is it
possible if the atom is neutral and has mass, if there are only electrons in the atom?
The existence of positively charged particles contained in atoms was hinted at by Eugen Goldstein around
1886. With the discovery of electrons, scientists increasingly believed that in an atom there must be
positively charged particles that are useful for balancing the negative charge of electrons. In
addition, if the only particles that make up an atom are electrons, then the sum of the masses of electrons
will be smaller than the mass of an atom.
In 1886, Goldstein also conducted an experiment using a gas cylinder that had a cathode and had been given
holes and then carried an electric charge. After that, the gas behind the cathode becomes lit.
This event shows that there is radiation originating from the anode that penetrates into the hole
in the cathode plate. The light is called anode light or positive light. The
properties of the anode rays are:
a. Anode rays are particle radiation, so they can rotate a propeller
In an electric or magnetic field, it is deflected to the negative pole, so the anode beam is
included in the positively charged radiation
c. The particles
present in the anode beam depend on the type of gas present in the tube
The results of this experiment proved that during the process of forming electrons towards the anode,
positive rays would also form going in the opposite direction through the holes in the cathode.
After trying to put various kinds of gases into the tube, it turns out that it is hydrogen gas that
can produce the light with the smallest positive charge, either in terms of mass or charge. So
the particle is called a proton. The mass of the proton is equal to 1 amu or atomic mass units
and the charge on the proton is equal to +1.
The presence of positively charged particles making up the atom was increasingly evident when Ernest
Rutherford, a person from New Zealand, moved to England in 1906 with his two assistants, named Hans Geiger
and Ernest Marsden. They then conducted a series of experiments to find out the position of the
particles in the atom. Their experiment is known as the scattering of alpha rays on a thin
sheet of gold. They then managed to calculate that the mass of the positively charged particle
was estimated to be 1,837 times that of the electron. Now we call it the proton.
The term was only recently used starting in 1919.
Mass of 1 electron = 9.11 × 10–28 grams
Mass of 1 proton = 1.837 × 9.11 × 10–28 grams = 1.673 × 10–24
From the three observations, it was found that the α particles fired at the thin gold metal plate, most of
them will be forwarded and some will be deflected. There are even some that are reflected.
It was quite a shock for Rutherford. His discovery led to the collapse of Thomson’s
atomic theory. In his experiments, the reflected α particles were thought to have hit something
solid in the atom. That way, the atom is not homogeneous as described by Thomson.
In fact, according to Marsden, there is a fact that one in 20,00 α particles will turn at an angle
of 90 degrees or even more.
Based on the symptoms described above, several conclusions were obtained including:
a. Atoms are not solid balls. Because almost all the particles in it are alpha
(α) passed on. That means, most of the atomic volume is empty space.
Particles that experience deflection are α particles that have approached the atomic nucleus.
This is because they both have a positive charge.
The reflected particles are α particles that have hit the atomic nucleus.
Based on the facts obtained from these experiments, Rutherford proposed the atomic capital that he
discovered and stated that the atom consists of a very small atomic nucleus and has a positive charge and is
surrounded by negatively charged electrons. The number of protons in the nucleus is equal to
the number of electrons surrounding the nucleus. So that the atom has a neutral nature.
Rutherford also considered that in the atomic nucleus there are neutral particles which function to
bind positive particles so they do not repel each other. From these experiments, Rutherford was
able to estimate the atomic radius to be approximately 10–8 cm and the core radius to be approximately 10–13
What Are Protons?
Protons are a type of subatomic particle, where these particles are the minimum particles that make up an
atom. In addition, the proton is also included in the fermion family which is equipped with a
positive electric charge. All matter is generally made of atoms and each turn consists of three
different types of particles, and is equipped with three types of electric charges, among others:
1. Electrons with a negative charge
2. Neutrons with a neutral charge
3. Protons with a
Characteristics of Protons
Protons are composite particles that are stable and much larger than electrons, which is 1,836 times as
described above. Apart from that, the proton is also endowed with a positive elementary charge
of 1 (1.6 x 10^-19 C). On the other hand, the proton itself is composed of three elementary
particles. The half-life of the proton is greater than 1035 years, in which case the proton is
very susceptible to decay. Then, the proton also has other subatomic particles and their own
spin. it is intrinsic and invariable angular momentum and within it is 1/2. This
property is very useful for nuclear magnetic resonance and is also used for other modern technological
Protons and neutrons have their own structure. Within the protons as well as the neutrons, we
can find elementary particles that are eternal. These particles are known as quarks.
In its core, protons and neutrons are connected through a considerable force, namely in the form of
interactions whose job is to regulate the behavior of quarks and form individual protons and neutrons.
Protong is often said to have a quark composition derived from uud. So that the
quantum number has the following charge:
q (uud) = ⅔ + ⅔ + (-1/3) = +1
The mass of the proton above is 938.272 MeV/c2. Meanwhile, the mass of the three quarks is
only around 12 MeV/c2, which is only about 1 percent of the mass energy of the neutron. As with
protons, most of the mass or energy that comes from neutrons is in the form of strong nuclear force energy
(gluons). Quark neutrons are then combined with gluons, which are exchange particles for the strong nuclear
Free protons or protons that are no longer bound to nucleons or electrons are stable particles that have
not been studied to spontaneously decompose into other particles. In addition, these free
protons are found naturally in a number of situations and conditions. For example, free protons
make up 90 percent of cosmic rays. Where the energy or temperature is high enough to separate
it from electrons that have an affinity. Proton decay is also related to the law of
conservation of baryon numbers. The Baryon number is a generalization of the nucleon number
conserved in reactions and also in non-relativistic nuclear decay.
The law states that:
The sum of the numbers in the baryon number originating from all the incoming particles is the same as the sum of
the numbers in the baryon number originating from all the particles resulting from the reaction.
Protons are usually found in the atomic nucleus, protons, and neutrons. Where the three are
often referred to as nucleons. On the other hand, electrons orbit around the three particles in
a dispersing manner. Then the atomic nucleus is associated with a fairly strong nuclear force.
Where in the case of large atoms like Uranium, they can produce other forces, such as
electromagnetic. The nucleons are the highest percentage of the mass of any atom.
Hence, they can determine the difference between chemical elements and other elements.
Like for example, the hydrogen atom which has only one proton in its nucleus. While
helium has two protons as well as one or two neutrons, depending on the specific isotope.
The atomic number of each element can be seen on the periodic table. Where the atomic number Z
usually indicates how many protons there are in a particular type of atom in its nucleus. Each
chemical element has a different atomic number. Although their behavior is equally determined
by the number of electrons orbiting the nucleus. So, for example, chlorine (CI) has 17 protons
in its nucleus. Hence the atomic number also amounts to 17. It never varies, even between
isotopes of the same atomic version. This is because they have different numbers of neutrons in
Proton’s Charge and Mass
In physics, a proton is a subatomic particle that has a positive charge of 1.6 × 10-19 coulombs and also has a
mass of 938 MeV (1.6726231 × 10-27 kg, or about 1.836 times the mass of an electron. An atom is usually composed
of a number of protons and also the neutrons in the atomic nucleus, as well as the number of electrons
surrounding the atomic nucleus.In a neutrally charged atom, the number of protons will be equal to the number of
electrons.Where the number of protons in the nucleus will usually be in charge of determining the chemical
properties of an atom. The nucleus of the atom is often referred to as the nucleus, nuclei, and also nucleons.
Then the reaction that occurs or is related to the atomic nucleus will be referred to as a nuclear reaction.
Protons usually have less mass than the neutrons that are in the nucleus. Yet they are 1,836
times more massive than electrons. The actual mass of the proton is 1.6726 x 10^-27 kilograms.
It is one very small mass. The “^ -” symbol will represent a negative exponent.
The number is the decimal point followed by 26 zeros, so the number becomes 16,726.
Inside the electric charge, the proton turns into a positive, no longer as a fundamental particle.
Precisely the proton is actually composed of three tiny particles which are usually called
Functions in Atom
The protons in the atomic nucleus are responsible for helping to bind the nucleus together. In
addition, protons will also attract negatively charged electrons. Where the number of protons
in the atomic nucleus will determine the chemical element. This number is known as the atomic
number or often represented by the capital letter Z.
Energy for the Stars
Inside the sun as well as in all other stars, these protons combine with other protons through nuclear
fusion. However, this fusion still requires a high rate of 1 million degrees Celsius.
This temperature will cause the two lighter particles to melt into a third particle.
The mass of the particle is less than that of the two initial particles combined.
Albert Einstein discovered in 1905 that matter and energy can be conserved from one form to
another. This explains how the loss of mass during the fusion process appears, which is the
energy from the star’s emission.
Example of Protons
It should be understood that free protons are real. The nucleus of the hydrogen atom as well
as the H+ ion are examples of free protons. Regardless of the isotope, each hydrogen atom will
have one proton. Then each helium atom will have two protons and each lithium atom will contain
three protons and so on.
Thus a complete explanation of the proton inventor, history,
definition, structure, properties, and more. For Sinaumed’s who are interested in studying
physics or chemistry in more depth, this material also needs to be understood and studied.
In order to increase knowledge of physics and chemistry. I hope the article is
easy to understand.