Short Answer

Physical properties of matter are the characteristics that can be observed or measured without changing the substance into a new one. Examples include colour, shape, mass, density, melting point, and boiling point. These properties describe the physical appearance or state of a substance.

Chemical properties of matter describe how a substance reacts and changes into a new substance. Examples include flammability, rusting, reactivity with acids, and ability to burn. These properties can be observed only during a chemical change. The main difference is that physical properties do not change the substance, while chemical properties form new substances.

Detailed Explanation :

Physical and Chemical Properties of Matter

Matter has many characteristics that help us identify, classify, and understand different substances. These characteristics are known as properties. Properties of matter are broadly divided into physical properties and chemical properties. The difference between the two is based on whether the substance changes its identity or remains the same while being observed. Understanding these properties is important in chemistry because they help us study substances, predict their behaviour, and use them safely.

Physical properties describe the external features and measurable qualities of matter, while chemical properties describe how a substance behaves during chemical reactions. Both types of properties help scientists determine the uses, nature, and behaviour of different substances.

Physical Properties of Matter

Physical properties are the characteristics of a substance that can be observed without changing its chemical identity. This means that when you measure or observe a physical property, the substance remains the same before and after the observation.

Key features of physical properties:

• Can be observed directly
• Do not involve chemical reactions
• Do not change the identity of the substance
• Describe appearance and measurable qualities

Common physical properties include:

• Colour – e.g., copper is reddish-brown; sulphur is yellow
• Odour – e.g., perfumes have a pleasant smell
• Mass and Volume – amount of matter and space occupied
• Density – mass per unit volume
• Melting point and Boiling point – temperatures at which substances change state
• Solubility – ability to dissolve in a solvent
• Conductivity – ability to conduct heat or electricity
• Shape and Size – visible characteristics

For example, ice melts to become water. The state changes, but the substance remains H₂O. This is a physical property.

Physical properties are useful for separating mixtures, identifying substances, and understanding their physical behaviour.

Chemical Properties of Matter

Chemical properties describe how a substance reacts with other substances to form a new product. These properties can only be observed during a chemical change. When a chemical property is tested, the original substance changes into a different one with new properties.

Key features of chemical properties:

• Observed only during chemical reactions
• Involve formation of new substances
• Change the identity and composition of the substance
• Indicate how a substance behaves in chemical processes

Common chemical properties include:

• Reactivity – how a substance reacts with air, water, acids, or bases
• Flammability – ability to burn in the presence of oxygen
• Rusting – reaction of iron with oxygen and moisture
• Combustion – reaction that produces heat and light
• Acidity and Basicity – chemical nature of substances
• Decomposition – breaking down into simpler substances

For example, iron reacts with oxygen and water to form rust. This is a chemical property because a new substance (rust) is formed.

Chemical properties help in understanding how substances behave in reactions, how they can be used in industries, and how safe or harmful they are.

Main Differences Between Physical and Chemical Properties

The key difference lies in whether the identity of the substance changes or remains the same.

1. Nature of Change
   • Physical properties do not create new substances.
   • Chemical properties create new substances.
2. Observation
   • Physical properties can be observed directly.
   • Chemical properties are observed only during a chemical reaction.
3. Examples
   • Physical: colour, melting point, density
   • Chemical: flammability, rusting, reactivity
4. Effect on Composition
   • Physical properties keep the composition unchanged.
   • Chemical properties change the composition.

Understanding these differences helps scientists identify substances, predict how they will react, and handle them safely in laboratories and industries.

Importance in Daily Life

Physical and chemical properties play a role in selecting materials for different uses:

• Metals are used for electrical wires because of their physical property of conductivity.
• Cooking involves chemical changes like browning and decomposition.
• Refrigerants are selected based on their physical boiling points.
• Medicines are made by understanding chemical reactivity.
• Rusting prevention requires knowledge of chemical properties.

These properties have practical applications in construction, medicine, agriculture, manufacturing, and household activities.

Conclusion

Physical properties describe the measurable and visible features of matter without changing its identity, while chemical properties describe how a substance reacts to form new substances. The main difference is that physical properties do not involve chemical change, whereas chemical properties involve the formation of new products. Understanding both types of properties helps us study matter, predict its behaviour, and use substances effectively and safely.