Difference Between an Atom vs a Molecule
Look around you. Everything you can lay your eyes on is made of matter. Even those things too small to see with the naked eye are classified as matter because they have mass and take up space. When matter is broken down to its foundational parts, you will discover the smallest particles in it.
In this article, we will discuss the difference between atom and molecule. They are otherwise known as the smallest constituent units of matter. You will be presented with their definitions, how they are different or similar, and a table showing the comprehensive relationship between the two terms.
Definition of an Atom
An atom is the most fundamental unit of an element. It constitutes the most defining structure of matter. According to scientists, there is no other particle of a substance smaller and simpler than its fundamental unit. This is not surprising because the term has a Greek origin and is translated as “indivisible.”
- Parts
There are three distinct parts of an atom. They are as follows.
- Protons, which are defined as stable particles with a positive charge
- Neutrons, known as sub-particles without electric charge
- Electrons, a sub-particle with a negative charge that functions as the primary carrier of electricity
Note that the protons and neutrons make up the nucleus.
- Properties
For a better understanding of the difference between molecule and atom, you will need to remember the properties of atoms, which include the following.
- Atomic number
- Atomic mass
- Relative atomic mass
- Radioactivity
- Electric charge
- Spin of electrons
Definition of a Molecule
A molecule is defined as a group of atoms bonded together to represent the minutest fundamental unit of a compound that can take part in a chemical reaction. Atoms may be the smallest unit ever of a particular element, but they cannot maintain a stable state on their own in most cases. Bonding with other atoms helps them maintain a level of stability that allows them to react chemically.
There are three different kinds of molecules.
- Mixture molecule
- Compound molecule
- Element molecule
Just in the same way that atoms come together to form a molecule, molecules also come together to form a compound. There are a lot of examples of molecules.
- Water – H20
- Table salt – NaCl
- Nitrogen – N2
- Glucose – C6H12O6
- Calcium oxide – CaO
- Ozone – 03
Have you been asking, “What is the difference between atoms and molecules?” One of the ways to answer that question is by pointing out the fact that nuclear bonding is required in the former, unlike in the latter, where covalent bonding is necessary to keep the components together in a stable state (or unstable in some cases).
Main Differences Between Atoms vs Molecules
Here is a table to show more of the differences between these two terms.
| Basis of Comparison | Atom | Molecule |
| Definition | The most fundamental unit of an element and the most defining structure of matter | Defined as a group of atoms bonded together to represent the minutest fundamental unit of a compound that can take part in a chemical reaction |
| Structure | The simplest particles that exhibit the properties of an element | Made of more than one atom |
| Existence | May or may not maintain stability in a free state | Can exist in a free state |
| Components | Nucleus and electrons | More than one atom bonded together by covalent bonds |
| Visibility | Cannot be seen or observed with the naked eye or any known magnifying instrument | Can only be seen with the help of a magnifying microscope |
| Type of bonding | Nuclear | Covalent |
| Rate of reactivity | Highly reactive in compatible conditions | Not as reactive |
In the future, you may find yourself wondering, “What’s the difference between molecule and atom at a very basic level?” This table sums up the basic things you need to understand. You can refer back to it. There is more to be revealed about this topic, but this should do for a comprehensive introduction.
Difference Between Atoms and Molecules: Conclusion
It can be said that these two terms are interrelated, but it would be incorrect to use them as if they had the same meaning. In comparison, the definition, components, structures, and properties of these substances vary from one another. The atom vs molecule comparison also exposes how the sizes and rate of reactivity of these two substances can be different.
