Difference Between Molecules and Compounds

Molecules and compounds are substances that form a part of the link between elements, but they carry with them an important difference. Molecules are formed by the bond between the atoms of the elements. On the other hand, compounds are formed when atoms of different elements combine and bond to give a compound. Molecules may or may not contain atoms of various types, but it is mandatory that compounds contain different types of atoms; least two separate atoms of different elements.

Comparison chart

What are molecules?

In a chemical element, a molecule is considered to be the smallest particle of its component elements, which has a fundamental similarity in its properties with these elements. Molecules are made up of atoms held together under strong chemical bonds. This bond can be electrovalent, that is, established by electron exchange, or covalent bond, which is the exchange of electrons. Molecules are identified among ions by their neutral nature, which means that the molecules carry no positive or negative charge with them. They are simply formed by the reaction of two atoms. For example, N2 and H2 are nitrogen and hydrogen molecules, respectively.

Compounds are those chemical substances that have been formed by the chemical bond between atoms of different elements. These different atoms carry a specific charge, positively charged atoms are electron deficient and negatively charged atoms are electron efficient. These two different atoms come together to enter the neutral state by bonding and producing a new compound entirely. For example, hydrogen atoms carrying a positive charge, H+, and oxygen atoms carrying a negative charge, O2-, chemically combine with proportional weight to form water, or H2O. Therefore, H2O is a compound since it is formed by the bonding of atoms of two different elements, hydrogen and oxygen.

Key differences

1. Molecules may or may not be the result of the combination of atoms of two different elements, but compounds are always formed when atoms of different elements are joined. That is why it is said that all compounds are molecular, but not all molecules are compounds.
2. A molecule can be very unstable by itself, since it is just the combination of two atoms, but a compound is very stable and has a physical form that is visible to the naked eye.
3. Molecules of the same elements can be in any state, solid, liquid, or gas. It can also vary in weight and amount, but a specific amount of two elements reacting together in a specific way will always give a uniform type of compound.
4. A molecule is the smallest unit of any substance formed by the bonds between atoms, while a compound is a complete unit resulting from the bonds between atoms of different elements.
5. Molecules are recognized by various factors such as their arrangement, size, and weight. But compounds can be identified simply by their chemical formula, since that formula is named after the elements that participate in the reaction and make the compound known.
6. Molecules carry no charge with them and are electrically neutral. On the other hand, compounds are formed when two oppositely charged elements react with each other and are linked by the covalent bond or electron sharing bond.
7. Further subdivision of a molecule is not possible, as it will lead to the breaking of molecules into their basic atomic structure, but compounds can be disintegrated into separate molecules.

Here, we can clearly see that molecules and compounds share a very fine line of difference, which if repeated, will be that molecules are made up of various atomic bonds and compounds are made up of the bonds between atoms of different elements. Apart from this, the differences in shapes, size, nature, and behavior create a greater separation between the two forms of a chemical and make it easier for us to distinguish between the two.