Properties of Matter: Definition, Physical Properties, Chemical Properties and Thermal Properties

Properties of Matter Overview

Matter, in its various forms, is the fundamental substance that makes up the universe. Everything we see, touch, or interact with is composed of matter. Understanding the properties of matter is crucial in numerous scientific disciplines, from chemistry and physics to materials science and engineering. In this article, we will explore the various aspects of matter, its properties, and how they can be categorized.

Matter: The Building Block of the Universe

Matter is defined as anything that has mass and occupies space. It is a broad term that encompasses all substances, whether they are solid, liquid, gas, or even plasma. Matter is composed of tiny particles called atoms, which are further composed of subatomic particles, including protons, neutrons, and electrons. These particles interact with each other through various forces, giving rise to the properties of matter we observe in the macroscopic world.

Properties of Matter

Properties of matter are characteristics or attributes that help us distinguish one substance from another and describe how matter behaves under different conditions. These properties can be broadly categorized into three main types: physical properties, chemical properties, and thermal properties.

Physical Properties of Matter

Physical properties are those characteristics that can be observed or measured without changing the fundamental composition of the substance. Some common physical properties include:

1. Mass: The amount of matter in an object, typically measured in grams or kilograms.
2. Volume: The amount of space occupied by an object, often measured in cubic centimeters (cm³) or liters (L).
3. Density: The mass of a substance per unit volume, which can provide insights into its compactness.
4. Color: The visual appearance of a substance, which can vary due to the interaction of light with its molecules.
5. Texture: The feel or appearance of the surface of a substance, such as smooth, rough, or gritty.
6. Melting Point and Boiling Point: The temperatures at which a solid turns into a liquid (melting) or a liquid turns into a gas (boiling).
7. Solubility: The ability of a substance to dissolve in a solvent, often described as "soluble" or "insoluble."
8. Conductivity: The ability of a material to conduct electricity or heat.
9. Magnetism: The property of being attracted to or repelled by a magnetic field.

Chemical Properties of Matter

Chemical properties describe how a substance interacts with other substances and undergoes chemical changes. These properties are typically observed when substances react with each other. Common chemical properties include:

1. Reactivity: The tendency of a substance to react with other substances, leading to the formation of new substances.
2. Flammability: The ability of a substance to ignite and burn in the presence of oxygen.
3. Corrosiveness: The tendency of a substance to degrade or deteriorate materials it comes into contact with.
4. Toxicity: The potential harm a substance may pose to living organisms.
5. pH: A measure of the acidity or alkalinity of a substance, which can influence its chemical behaviour.

Thermal Properties of Matter

Thermal properties are related to how matter responds to changes in temperature. These properties include:

1. Specific Heat Capacity: The amount of heat energy required to raise the temperature of a substance by a certain amount.
2. Thermal Conductivity: The ability of a material to conduct heat, determining how quickly heat flows through it.
3. Thermal Expansion: The tendency of matter to expand when heated and contract when cooled.

Properties of Matter: Difference

The table below shows the difference between Chemical and Physical Properties:

Properties of Matter: Extensive and Intensive Properties

The characteristics of matter, encompassing both its physical and chemical attributes, can be categorized into two main types: extensive properties and intensive properties.

• Extensive Properties: Extensive properties pertain to attributes that vary depending on the quantity of matter within a specific sample. For instance, the mass and volume of an object are contingent on the amount of matter it contains. When we introduce 5kg of water into a 10kg water bucket, both the mass and volume increase, resulting in a total mass of 15kg. This illustrates that the mass of water expands in tandem with the quantity of water added.
• Intensive Properties: Intensive properties, conversely, relate to characteristics that remain unaffected by the quantity of matter within a given sample. Examples of intensive properties include color, density, boiling point, and melting point. Suppose we have a 10kg bucket of blue-colored water and subsequently introduce another 5kg of blue-colored water into it; in this scenario, the color remains consistent. Similarly, the boiling and melting points of water remain unaltered.

Note: Mass and volume both are extensive properties but their ratio called density is an example of intensive property.

Density= Mass/Volume

Properties of Matter: Chemical and Physical Change

Matter can undergo two fundamental types of changes: chemical and physical changes.

Chemical Changes:

• When things go through chemical changes, it means their tiny building blocks (molecules) get rearranged. This happens because the bonds that hold the molecules together break, and new bonds form.
• Chemical changes make things become something entirely different. Imagine if something had a set of features, like how hot it needs to get before it turns to liquid or its color. During a chemical change, these features change into new ones. Chemical changes are tricky to undo because they change the very stuff that makes something what it is. For example, if you burn a piece of paper, you can't turn the ashes back into paper because the paper's basic building blocks have changed.

Physical Changes:

• Now, when things go through physical changes, the building blocks stay the same – they don't get rearranged through chemical bonds.
• Physical changes are like giving something a new look or shape without changing what it's made of. Think about an ice cube. When it melts, it turns into water, but it's still made of the same stuff - two tiny parts of hydrogen and one part of oxygen. So, the chemical makeup doesn't change, and things like how hot or cold it needs to be to change, or its color, stay the same.
• The cool thing about physical changes is that they are often reversible. For example, you can turn that melted ice back into a solid ice cube by freezing it again, and if you dissolve salt in water, you can get the salt back by letting the water evaporate (disappear as vapor).

Things to Remember

Understanding the properties of matter is essential in various scientific fields and everyday life. Here are some key takeaways:

1. Matter comprises atoms and subatomic particles.
2. Properties of matter include physical, chemical, and thermal properties.
3. Physical properties can be observed or measured without changing the substance's composition.
4. Chemical properties describe how substances interact and change chemically.
5. Thermal properties relate to how matter responds to temperature changes.
6. Extensive properties depend on the amount of substance, while intensive properties are independent of quantity.
7. Matter can undergo physical and chemical changes, with the latter involving a change in composition.