Everything About the Atom - Protons, Neutrons, Electrons, Atomic Number and Mass, Atomic Structure, Isotope, Isobars, Isotones, Ions, Compounds and Molecules

What is an Atom?

An atom is a building block of matter, used to determine the characteristics of an element. Element is a pure substance consisting of only one type of atom, defined by its atomic number. An atom is the smallest unit of matter that retains the chemical properties of an element. Atoms are constantly interacting with each other and can combine to form molecules, which are the building blocks of most of the matter that we encounter in our everyday lives. These interactions determine the state of matter the atoms are in, as they can be found as solids, liquids, or gases. Democritus was the person who first suggested the existence of ATOM & coined the name ATOMOS means Not to be cut or Indivisible.

What are the Parts of an Atom?

Atoms are composed of three basic particles. These particles known as subatomic particles, consisting of protons (positively charged), neutrons (no charge), and electrons (negatively charged). These are the parts of the atom.

The atomic structure of these building blocks is very interesting. The protons and neutrons are located in the center of the atom, while the electrons are quite far from the center. The neutrons and protons in an atom are so closely packed together that they form a single cluster called the nucleus of the atom. Protons and neutrons are both called nucleons. The number of neutrons in the nucleus can vary, but the number of protons and neutrons usually add up to the atomic mass of the atom. Electrons are little particles whirling around the nucleus much as the planets orbit about the sun. Electrons stay in their orbits rather than fly off into space because of electrical attraction. The best example is helium. It has two protons and two neutrons in the centre of each atom with two electrons circling around it.

What is Protons, Neutrons and Electrons :-

Protons :-

Protons are positively charged subatomic particles, found in the nucleus of all atoms. The charge of a proton is +1. The number of protons in the nucleus of an atom determines its atomic number and its identity as a specific element. For example, all hydrogen atoms have one proton in their nucleus, while all carbon atoms have six protons. Protons have a positive charge.

Neutrons :-

A neutron is a neutrally charged subatomic particle, found in the nucleus of all atoms except hydrogen. A neutron has a mass of slightly more than a proton. Neutrons have a neutral charge means it has no charge. The number of neutrons in the nucleus can vary. Neutrons are important because they determine the isotope of an element. For example, a carbon with 6 neutrons is carbon-12, but add two more neutrons and you get carbon-14,

Electrons :-

Electrons are the subatomic particles that orbit the nucleus of an atom. Electrons have a negative charge, and are far away from the nucleus. They are much smaller than protons or neutron. In fact, they are 1,800 times smaller. They also carry electricity. The charge of an electron is -1. An electron carries a charge of 1.6 x 10-19 coulombs.

For each proton in the nucleus, the atom has one orbital electron. In other words, the number of orbital electrons in an atom is equal to the number of protons in its nucleus. Hydrogen with one proton in its nucleus has one orbital electron. Helium with two protons has two orbital electrons. The charge on the proton and electron are exactly the same in magnitude, but opposite in sign. Because of opposite charges, protons and electrons attract each other. Since the charge of a proton is equal but opposite to that of the electron, the total positive charge of the nucleus therefore equals the total negative charge of all the orbital electrons. In this way the net charge of the whole atom is exactly zero. The net charge of an atom is determined by the difference in the total number of electrons and protons. If an atom were short of an electron for any reason, it would have a positive charge. It would then pick up any loose electron that happened to be drifting around and so cancel out the extra positive charge. If an atom contains more electrons than protons, the net charge is negative. Example: An atom containing 5 protons and 3 electrons, has a +2 net charge.

What is Atomic Number and Atomic Mass?

Atomic Number :-

The number of protons in the nucleus, which makes atoms different from one another in their structure and character, is such an important number that it is given a special name, the atomic number. The atomic number of an element is found through the number of protons present in the nucleus. Example: carbon has 6 protons in its nucleus, making it also the sixth element in the periodic table. So the atomic number tells us how many positive charges there are in the nucleus, and of course, it also tells us how many orbital electrons the atom should have.

Atomic Mass :-

The atomic mass can also be calculated by adding the number of neutrons and protons. This is due to electrons having a really small mass, therefore not significantly contributing to the atomic mass. Example: An oxygen atom containing 8 protons and 8 neutrons, has an atomic mass of 16 amu. What is 1 amu? Well then, what is the mass of a proton? You could express the mass of a proton in pounds or kilograms, but you can imagine that it would be a small and difficult fraction to deal with. Instead scientists have created the atomic mass unit. The masses of the proton and neutron are nearly equal and we shall take them both as being 1 amu.

Atomic Structure :-

Now you are thinking how protons, neutrons, and electrons are arranged in an atom. We will explain. Nucleus is surrounded by spheres. These spheres are known as electron shells. The electron shells are located on the outermost region of an atom surrounding the nucleus. The farther away from the nucleus the shell, the more energy the electron has. Electrons can move rather easily from one atom to another in some materials. High levels of radiant energy, extreme heat, or the presence of an electric field (discussed later) can “knock” or “throw” electrons loose from atoms, upsetting the balance. So in other substances, it is difficult to get electrons to move. But in any case, it is far easier to move electrons than it is to move protons.

What is an Isotope, Isobars, Isotones?

Isotopes :-

Isotopes are various forms of an element that have the same number of protons but a different number of neutrons. Some elements, such as carbon, potassium, and uranium, have multiple naturally-occurring isotopes. Isotopes are defined first by their element and then by the sum of the protons and neutrons present.

Carbon-12 contains six protons, six neutrons, and six electrons; therefore, it has a mass number of 12 amu (six protons and six neutrons).

Carbon-14 contains six protons, eight neutrons, and six electrons; its atomic mass is 14 amu (six protons and eight neutrons).

Applications :-
Sodium-24 is used to find leaks in gas and oil pipelines, as well as ventilation systems. To control the thickness of plastic sheets, Krypton-85 radiation is utilised. Cobalt-60 gamma rays are used to destroy germs in food, causing it to degrade without damaging its flavour, freshness, or texture. Cobalt-60 emits gamma rays, which can be used in radiation to treat cancer. For superficial cancers like skin cancer, less penetrating radiation such as strontium-90 or phosphorus-32 is employed. Iodine-131 can also be used to treat thyroid disease.

Isobars :-

Isobars can be defined as elements with various atomic numbers but the same mass number. They also have varied chemical properties due to the difference in electron counts. Because an additional number of neutrons compensates for the amount of nucleons, an isobar has the same atomic mass but a different atomic number.

Applications :-
Uranium isobars can be used in nuclear reactors. Iodine isobars are used to treat goitre. Isobars of cobalt can be used to treat cancer. Phosphorus isobars are used to treat blood cancer. In nuclear physics and radioactivity, isobars are frequently researched. In the study of beta decay, they naturally arise. Isobar is a helpful classification criterion.

Isotones :-

Isotones are nuclides that have the same number of neutrons and differ in the number of protons, i.e., they would be different elements as a change in protons changes the atomic number. Examples of isotones include Carbon -12, Nitrogen -13 and Oxygen -14. These atoms all have six neutrons and six, seven, and eight protons. Sulphur-36, chlorine-37, argon-38, potassium-39 and calcium-40 are all isotones of 20 because they have 20 neutrons

Applications :-
Isotonic solutions are widely used in medicine as our body shows the property of maintaining constant temperature and pressure, so every fluid taken inside should be isotonic, or this may create severe consequences. Technetium-99 is used in medical imaging, which is produced by neutron radiation of molybdenum-98 targets. Isotopes that lead to higher cross-sections produce more products and therefore are more efficient. Another application is in the production of fissionable material for nuclear weapons. In addition to its use in military applications, isotones can be used as neutron absorbers for reactor control.

What is Ions, Compounds and Molecules?

Ions :-

When an atom participates in a chemical reaction that results in the donation or acceptance of one or more electrons, the atom becomes positively or negatively charged. This frequently happens for most atoms to have a full valence shell. This can happen either by gaining electrons to fill a shell or by giving away electrons to empty a shell. An atom with an electrical charge positive or negative is an ion. A positively charged ion is known as a cation. A negatively charged ion is known as an anion. Atomic number of Potassium (K) is 19. It has just one electron in its valence shell. During chemical reactions it donates one electron. As result potassium ion become slightly positive. Atomic number of fluorine (F) is 9. It has seven electrons in its valence shell. During chemical reaction Fluorine accepts one electron to bond with other atoms. When it does, its electrons will outnumber its protons by one, and it will have an overall negative charge. The element’s identity remains the same, no matter how great the excess or shortage of electrons.

Compounds :-

Different elements can join together to share electrons. When this happens, the result is a chemical compound.
For example, the compound glucose is an important body fuel. It is always composed of the same three elements: carbon, hydrogen, and oxygen. There are literally thousands of different chemical compounds that occur in nature.

Molecule :-

When atoms of elements join together by chemical bond to form a compound, the resulting particles are molecules. Molecules may consist of atoms of the same element, like a molecule of oxygen gas, formed by bonding between two oxygen atoms. These molecules known as homodiatomic molecules. Molecules may be formed by bonding between atoms of different elements, like a molecule of carbon dioxide gas, formed between oxygen and carbon atoms. These molecules known as heterodiatomic molecules.