Difference Between Molecule of Element and Molecule of Compound

The key difference between molecule of element and molecule of compound is that the molecule of element contains only one type of atoms whereas the molecule of compound contains two or more types of atoms.

A molecule is a combination of two or more atoms. We can classify molecules into different categories according to the number of atoms, types of atoms, chemical bonding between atoms, etc. Molecule of element and molecule of compound are such two categories which we classify according to the types of atoms present in the molecule.

CONTENTS

1. Overview and Key Difference
2. What is Molecule of Element
3. What is Molecule of Compound
4. Side by Side Comparison – Molecule of Element vs Molecule of Compound in Tabular Form
5. Summary

What is Molecule of Element?

Molecule of element is a combination of two or more atoms of the same type. This means these molecules are made out of the atoms of the same chemical element. We can further classify them according to the number of atoms present in the molecule. For example, diatomic molecules of element have two atoms of the same chemical element. The atoms of these molecules bind with each other only via covalent chemical bonding.

Examples of Molecules of Element

Some examples of molecules of element are as follows:

• O₂
• Cl₂
• Br₂
• H₂
• O₃

What is Molecule of Compound?

Molecule of compound is a combination of two or more atoms of different types. This means, these molecules have different combinations of different chemical elements. Same as molecule of element, we can further classify them according to the number of atoms present in the molecule. The chemical bonding between the atoms can be either covalent bonds or ionic bonds. Ionic bonds always form between cations (positive ions) and anions (negative ions). Therefore, ionic bonds always form between two different chemical elements.

Examples of Molecules of Compound

Some examples of molecules of compound are as follows:

• H₂O, NH₃, SO₃ are molecules of compound with covalent bonding.
• NaCl, KCl are molecules of compound with ionic bonding.

Difference Between Molecule of Element and Molecule of Compound?

Molecule of element is a combination of two or more atoms of the same type. It has atoms of one chemical element. On the other hand, the molecule of compound is a combination of two or more atoms of different types. It has atoms of two or more chemical elements. This is the key difference between molecule of element and molecule of compound. Moreover, the molecule of element has covalent chemical bonds but, the molecule of compound has either covalent or ionic chemical bonds.

Summary – Molecule of Element vs Molecule of Compound

Molecule of element and compound are two different categories of molecules. The difference between molecule of element and molecule of compound is that the molecule of element contains only one type of atoms whereas the molecule of compound contains two or more types of atoms.

Reference:

1. “Molecule.” Wikipedia, Wikimedia Foundation, 15 July 2018. Available here
2. Helmenstine, Anne Marie, Ph.D. “What Is the Difference between a Molecule and a Compound?” ThoughtCo, Jun. 22, 2018. Available here    

Image Courtesy:

1.’Covalent bond hydrogen’By Jacek FH – Own work, (CC BY-SA 3.0) via Commons Wikimedia  
2.’Water molecule 3D’By Dbc334 (first version); Jynto (second version) (Public Domain) via Commons Wikimedia