Compounds and Their Properties

A compound is a pure substance formed when two or more elements combine chemically in a fixed ratio. The elements lose their individual properties and the compound formed has new properties.

Characteristics of Compounds

• Compounds are formed by chemical combination of elements.
• The composition of a compound is always fixed.
• Properties of a compound are different from its elements.
• Compounds cannot be separated by physical methods.

Properties of Compounds

Some important properties of compounds are:

• They have a fixed chemical formula.
• They have a definite melting and boiling point.
• They are usually homogeneous in nature.
• They undergo chemical reactions to form new substances.

Examples of Compounds

1. Water (H₂O)
Formed by chemical combination of hydrogen and oxygen in the ratio 2:1. Water is a liquid used for drinking, washing, and many daily activities.

2. Carbon Dioxide (CO₂)
Formed from carbon and oxygen. It is a gas used by plants for photosynthesis.

3. Sodium Chloride (NaCl)
Formed from sodium and chlorine. It is commonly known as common salt and is used in food.

Difference Between Elements and Compounds

Elements	Compounds
Consist of only one type of atom.	Consist of two or more elements chemically combined.
Cannot be broken down chemically.	Can be broken down by chemical methods.
Example: Oxygen, Iron	Example: Water, Salt

Conclusion

Compounds are important substances that form the basis of materials used in daily life. Understanding compounds helps us know how different substances are formed and used around us.