The matter is made up of atoms. According to Northwestern University, matter constitutes the whole of the cosmos, except for energy. Because it was formerly believed that atoms were the tiniest objects in the world and couldn’t be separated, the word “atom” derives from the Greek word meaning “indivisible. Today, we know that atoms are made up of three subatomic particles, which are even smaller than previously thought: protons, neutrons, and electrons. These smaller particles, known as quarks, make up the subatomic particles.

After the Big Bang, atoms were made about 13.7 billion years ago. Quarks and electrons were able to develop when the dense, hot cosmos cooled. Protons and neutrons were formed from quarks, and these nuclei were formed as a result. During the initial few minutes of our universe’s existence, all of this occurred.

To create atoms, nuclei had to wait 380,000 years for the cosmos to cool down enough to slow down electrons enough for them to be captured by nuclei. Jefferson Lab reports that hydrogen and helium are the most common elements in the universe and were the first atoms to form. Eventually, gravity brought together gas clouds to form stars, and as the stars burst, heavier atoms were released into the cosmos (supernova).

What is an Atom?

An atom is an elementary particle. An atom is the unit of measure corresponding to the smallest possible quantity of a chemical element. When it comes to gold, the lowest amount of gold you can have is one atom of metal. There is nothing small about the term “nano”! Compared to human hair, atoms are tens of thousands of times smaller.

As a result, only a super-powerful electron microscope can show you one. In order to understand how the world around us is made up of various atoms, it is necessary to dissect it. The most common building blocks for living things are the triatomic elements hydrogen, carbon, and oxygen. It’s important to remember that scientists have found just three of the 100 known chemical elements. When you combine atoms from various elements like LEGO pieces, you can create anything.

Basic Properties

• Atomic Number

An atom’s atomic number (denoted by the symbol Z), the number of protons in the nucleus, is the essential feature. Carbon, for example, has a Z of 6, but uranium has a Z of 92. A neutral atom is one that has an equal number of protons and electrons, which results in a positive and negative charge balance that is in perfect harmony. It is the number of protons in the nucleus that defines an atom’s chemical characteristics since electrons govern how one atom interacts with another.

• Atomic Mass And Isotopes

Nuclear neutron count does not affect an atom’s chemical characteristics, but it does on mass. Because of this, even if two nuclei with different weights have the same number of protons and neutrons have distinct chemical characteristics. Isotopes are identical nuclei in terms of their number of protons but have varying quantities of neutrons compared to one another. The isotopes of all chemical elements are many.

Parts of An Atom

Atoms are composed of three parts: protons, electrons, and neutrons. Neutrons and protons make up the core of an atom. The nucleus refers to that region. On the other hand, considerably tiny electrons are whizzing by.

1. Electrons

The nucleus is surrounded by electrons, which are negatively charged and organized in shells or orbits. They have a charge of -1 compared to each other. Every atom has the same number of electrons as protons in its nucleus.

Electrons’ Characteristics:

• Electrons have a charge of -1e, or about -1.602 10-19 coulombs.
• An electron has a mass of 9.1 10-31 g.
• Electrons are not considered when determining an atom’s mass because of their insignificance.

2. Protons

The charge on protons is always positive. The atomic number is the number of protons in an atom (also called the proton number). Atoms are listed in the Periodic Table by atomic number. The charge of protons is +1.

Proton’s Characteristics:

• An atom’s positively charged protons are just that: protons. A proton has a charge of 1e, which is roughly 1.602 10-19 electrons.
• An element’s atomic number is directly proportional to the total number of protons inside its atoms.
• It has a mass of around 1.672 10-24.
• Protons are 1800x heavier than electrons.

3. Neutron

Neutrons have neither a positive nor a negative charge; they are neutral. In all atomic nuclei, except for hydrogen, neutrons are present. Together with protons and neutrons, they make up 99.9 percent of an atom’s mass in the nucleus, the atom’s most dense region.

Neutron Characteristics:

• Neutrons have almost the same mass as protons, which is 1.674 10-24.
• Neutrons are fundamental particles that do not carry any electric charge since they are electrically neutral.
• Isotopes of a given element all have the same number of protons, but their nuclei contain different numbers of neutrons due to the different proportions of neutrons to protons.

4. Nucleus

The atomic nucleus has its core here. Protons and neutrons make up the nucleus. This means that most of the atom’s volume is occupied by the nucleus, which is only around one-tenth of the atom’s diameter. When depicting atomic structures, electrons are often shown revolving in orbits around the nucleus as part of the drawing. More precisely, electrons move so quickly that you can never tell where they are.

5. Electron Cloud

It is the part of the atom that is located outside the nucleus. Electron clouds, which surround an atomic nucleus and are related to an atomic orbital, are negatively charged areas that surround the nuclei. Theoretically, it is described as a region with a high probability of containing electrons. The atomic number is a term used to describe the number of protons in an atom. It’s easy to tell if an atom is a hydrogen by looking at its atomic number, 1. 

A helium atom is shown as the second atomic number. The total number of neutrons and protons is used to compute the relative atomic mass. While hydrogen is the most abundant element in the universe, helium is the most abundant element because of its four-atom structure. The density of helium is four times that of hydrogen to give you an idea of how dense the two are.

How Can We Tell If Atoms Exist?

How can we know it exists if we can’t see the atoms? The scientific method is well-known for providing evidence for its theories and hypotheses. As a result, there is a wide range of evidence to support the existence of atoms. Big atoms have been deliberately broken down into smaller ones by scientists. Ernest Rutherford was the leader of a team that, based on a series of viral experiments in the early 20th century, shot particles at atoms and carefully examined the interaction results. It showed how the orbits of atoms were ordered on the inside.

There are also radioactive materials, which spontaneously decompose into smaller components and release microscopic particles. When atoms exist and are composed of smaller particles, all of this makes logical. A smattering of other data has also shown the existence of electron particles. They have made a significant contribution to the development of magnetism and electricity.