Elements and compounds are two terms that we often read about while preparing for our chemistry exams. To be able to understand them thoroughly, we need to learn the key differences between them.
The main difference between element and compound is the type of atom. An element is a purest chemical substance that is made up of the same (only one) kind of atoms while a compound is made up of two or more kinds of atoms in a fixed ratio.
Both elements and compounds are substances, but they differ from each other based on substances that are combined and through atomic bonding. Elements are categorized into three forms,
- Metal
- Non-metal
- Metalloid
While compounds, on the other hand, are categorized based on their bonding into three forms,
- Ionic
- Metallic
- Molecular
To learn the in-depth differences between an element and the compound, look at the comparison chart below.
Comparison Chart
| Element | Compound | |
| Definition | An element is a purest chemical substance that is composed of same type of atoms that exhibit the same properties as that of the element | A compound is formed when two or more different types of elements combined chemically in a fixed ratio |
| Ability to Break |
The element cannot be broken down into simpler substances by any chemical or physical method |
Compounds can be easily broken down into simpler substances by chemical reactions |
| Composition | An element is composed of one kind of atom that has the same number of protons in their atomic nuclei | A compound is made up of mainly two or more than two elements that are chemically combined in a fixed ratio and are arranged in a defined manner through chemical bonds |
| Representation | Every element is represented by a unique symbol that is designed by IUPAC. For example, carbon is represented by C in the periodic table | Compounds are represented by their chemical formula that is a symbolic representation of the number of atoms present in each element in a single molecule of a compound. For example, water is represented by the chemical formula H2O |
| Distinguishing Feature | Elements are differentiated from each other based on their name, symbol, atomic number, boiling point, melting point, ionization energies, and density | Compounds are differentiated from each other based on their fixed ratio of different elements (arranged in a defined manner) |
| Types | There are three main types of metals classified as metal, non-metal, and metalloids (semi-metal) | Compounds are classified into three main types according to their chemical bonds which can be ionic, metallic, and molecular |
| Total Numbers | There are about 117 elements identified at present and out of which 94 elements are found naturally on Earth-like carbon, hydrogen, nitrogen, oxygen, other. | Compounds are uncountable |
What is Element?
“Element is the purest form of a chemical substance that is made from a single type of atom.” In other words, all the atoms present in an element will have the same number of protons.
Examples of elements include oxygen, hydrogen, iron, helium, and gold.
Forms of Element
Though all elements are made from the same type of atoms, they come in different forms. Depending on the temperature, they can be solid, liquid, or gas. They can also take different forms depending on how tightly the atoms are packed together and are called allotropes.
One common example of allotropes is carbon. Depending on the arrangement of carbon atoms, they can form diamond, coal, and graphite.
Number of Elements
There are billions of compounds, but only about 118 elements are discovered until today. Out of these 118 elements, only 94 occur naturally on Earth.
Types of Elements
Some elements are grouped if they share the same properties with each other. Below are some of the examples,
Alkali Metals
All the elements in this group have only one electron in the outer shell of their atom and are very reactive. Some examples are,
- Lithium
- Sodium
- Potassium
- Cesium
- Rubidium
- Francium
Noble Gases
As the name indicates, they are unique and have a huge number of electrons present in their outer shell. They are less reactive and are often used as signs as they glow in bright colors when the electric current is passed through it. For example,
- Neon
- Argon
- Xenon
- Radon
- Krypton
- Helium
What is Compound?
“Compounds are substances that are composed of two or more different types of elements that are chemically joined together in fixed proportions.”
For instance, water is a compound made up of two elements,
- Hydrogen
- Oxygen
Both of these elements are chemically combined in a fixed proportion of 1:8 by mass.
Types of Compounds
There are three main types of compounds called ionic compounds, molecular compounds, or acids.
Ionic Compounds
When metals and nonmetals react, they form ionic compounds. In general, an ionic bond is the electrostatic force of attraction between two oppositely charged ions.
Example
Salt is one of the examples of an ionic bond that consists of Na (Sodium) which is a positively charged metal that combines with Cl (Chlorine) that is a negatively charged non-metal.
Molecular Compound
Molecular compounds are made up of combinations of non-metals. A binary molecular compound is made up of only two elements. Examples: H2O (water).
- A molecule is made when two or more atoms join together chemically
- A compound is a molecule that consists of at least two different elements
- All compounds are molecules, but then not all molecules are compounds
- Molecular compounds are easy to recognize, as they consist merely of two non-metal elements.
- Molecular compounds are non-conductors of electricity
Example
- H2O (Hydrogen and Oxygen elements Water)
- CH4 (Carbon and Hydrogen elements Methane)
Acids
Acids are hydrogen containing compounds. Acids are easy to recognize they are composed of hydrogen and an anion (the hydrogen always comes first), and they have no charge.
Types of Acidic Compounds
Examples of different types of Acids are made up of hydrogen and anions, and they do not have charges:
- H2SO4(Sulfuric acid)
- HNO3(Nitric acid)
Key Differences between Compound and Element
- A compound consists of more than one atoms chemically combined in a fixed ratio while an element is a pure chemical substance that is made up of only one type of particle.
- A compound can be broken down into simpler substances by chemical reactions while an element cannot be broken down by chemical reactions.
- Their chemical formula signifies a compound. For example, salt is represented by the formula NaCl while symbols and numbers represent an element. For example, oxygen is represented by O.
- Compounds are classified based on their bonds and can be ionic, molecular, or acidic while elements are classified as metals, non-metals, or metalloids.
- Compounds are countless while there are nearly 118 elements identified and out of which 94 occur naturally on Earth.
Comparison Video
Conclusion
There are many differences between compound and element, but the key difference between them is the type of atom. A compound is a chemical substance that is made up of different types of atoms that are chemically arranged in a fixed ratio, while an element is a pure substance that is made up of one type of atom.