Differences Between Protons, Neutrons, and Electrons Explained
The history of the atom begins with a Greek philosopher named Democritus around 450 B.C. He wondered what would happen if we cut a piece of matter, such as chalk, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into further small pieces.
He called those pieces ‘atomos’. In the year around 1800, a British chemist named John Dalton revived Democritus’s early ideas about the atom. He did many experiments that provided evidence for atoms.
He researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio.
He also comes with Dalton's Atomic Theory. One of his theories states that All substances are made of atoms, and they are the smallest particles of matter. They cannot be further subdivided into smaller particles. However, in the early 20th century, some scientists like J.J Thomson, Rutherford, etc, showed that atoms can be further subdivided into smaller parts, and the three subatomic particles of an atom are proton, electron, and neutron.
3 Subatomic Particles of an Atom
The number of subatomic particles in an atom is three which includes Proton, Neutron, and Electron. Each of them is discussed below.
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Proton Subatomic Particle
Protons and Neutrons together make the nucleus of an atom and are also called nucleons. Proton was first discovered by Ernest Rutherford in the year 1919 when he was performing his gold foil experiment. He projected alpha particles (called helium nuclei) at gold foil, and the positive alpha particles were deflected. From that, he concluded that a proton exists in a nucleus and protons are the subatomic particles that are positively charged. The atomic number of an atom is the number of protons present in an atom. The mass of a proton is 1.676 x 10-24 gramsand the charge is 1.602 x 10-19 Coulombs.
Electrons
Electron was discovered by John Thomson in the year 1897. They are the negatively charged subatomic particles that revolve around the nucleus of an atom and are located in an electron cloud, which is the area surrounding the nucleus of the atom. The electrons can be removed or gained by an atom to form an ion. These positive and negative charged ions come together to participate in chemical bonding.
The mass of an electron is negligible as compared to the mass of a proton. It is found to have a mass equal to (1/1837) times the mass of a proton. The charge of an electron is 1.602 x 10-19 Coulombs. The 3 subatomic particles of an atom also include Neutron.
Neutron
Neutron was discovered by James Chadwick in the year 1932, They are located in the nucleus with the protons. Neutron along with protons make up the nucleons. They do not carry any charge like proton or electron. The neutron determines the isotope of an atom and its stability. The number of neutrons in an atom is not necessarily equal to the number of protons. The mass of a neutron is 1.676 x 10-24 grams and it is electrically neutral.
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Did You Know?
The Greek philosopher Aristotle, who lived about 100 years after Democritus, rejected Democritus’s idea of atoms. In fact, He thought the idea of atoms was ridiculous and ideas were accepted for more than 2000 years. After that, Dalton’s theory of Atom come into existence.
FAQs on Subatomic Particles of Atom: Complete Guide for Students
1. What are the three main subatomic particles of an atom?
The three main subatomic particles that constitute an atom are protons, neutrons, and electrons. Protons and neutrons are located in the central core of the atom, known as the nucleus, while electrons orbit this nucleus in specific energy shells.
2. Why is an atom considered electrically neutral despite containing charged particles?
An atom is electrically neutral because it contains an equal number of positively charged protons and negatively charged electrons. The positive charge of a proton (+1) and the negative charge of an electron (-1) are equal in magnitude but opposite in sign. These charges cancel each other out, resulting in a net charge of zero for the atom as a whole. Neutrons, being neutral, do not affect this balance.
3. What is the difference between an atom's atomic number and its mass number?
The primary difference lies in which subatomic particles they count. The atomic number (Z) of an element is equal to the number of protons in the nucleus of its atom; this number uniquely identifies an element. The mass number (A) is the total count of protons and neutrons combined within the nucleus. Therefore, the mass number defines the specific isotope of that element.
4. What is an easy way to remember the charges of the subatomic particles?
A simple mnemonic can help you remember the charges:
Proton starts with 'P', just like Positive. So, protons have a positive charge.
Neutron sounds like Neutral. So, neutrons have no charge.
Electron is the remaining particle, which carries a negative charge.
5. What are isotopes, and what is their importance in real-world applications?
Isotopes are versions of an element that have the same number of protons (and thus the same atomic number) but different numbers of neutrons. For example, Carbon-12 has 6 neutrons, while Carbon-14 has 8 neutrons. Their importance is significant in various fields: Carbon-14 is used in radiocarbon dating to determine the age of ancient artifacts, and isotopes like Cobalt-60 are used in medical radiotherapy to treat cancer.
6. Can you provide examples of the subatomic particle count for common elements like Carbon and Oxygen?
Certainly. For the most common isotopes of these elements, the counts are as follows:
Carbon-12 (¹²C): It has an atomic number of 6. Therefore, it contains 6 protons, 6 electrons, and (12 - 6) = 6 neutrons.
Oxygen-16 (¹⁶O): It has an atomic number of 8. Therefore, it contains 8 protons, 8 electrons, and (16 - 8) = 8 neutrons.
7. What is the specific importance of each subatomic particle to an atom's properties?
Each particle plays a crucial role in defining an atom's identity and behaviour:
The number of protons determines the element's atomic number (Z) and its fundamental identity.
The number of neutrons determines the atom's isotope and contributes to its mass and nuclear stability.
The number and arrangement of electrons govern the atom's chemical properties, including its reactivity and ability to form chemical bonds with other atoms.
8. Are protons and neutrons considered truly fundamental particles?
While protons and neutrons are fundamental to chemistry, in particle physics, they are not considered truly fundamental. They are composite particles made up of even smaller units called quarks. A proton is made of two 'up' quarks and one 'down' quark, while a neutron consists of one 'up' quark and two 'down' quarks. The electron, however, is considered a truly fundamental particle as per the Standard Model of particle physics.
