Chapter: 01. Matter
Self-Study Document: Exploring Matter
LEARNING OUTCOMES
By the end of this study, you will be able to:
Describe what matter is made of. List the unique properties of solids, liquids, and gases. Classify different objects as solids, liquids, or gases. CONNECTING TO WHAT YOU ALREADY KNOW
Think about the things you see every day – the chair you sit on, the water you drink, the air you breathe. All these are examples of solids, liquids, or gases.
Consider these everyday situations:
A glass of juice with ice and a straw: The bubbles are gas, the glass is solid, and the drink is liquid. A kettle boiling water: The kettle is solid, the water vapour (steam) is gas, and the water inside is liquid. A bottle of milk: The bottle is solid, the milk is liquid, and the air inside (and possibly bubbles) is gas. A person holding an umbrella in the rain: The umbrella is solid, the wind is gas, and the rain is liquid. INTRODUCTION: What is Matter?
Everything around us, whether it’s living or non-living, made by humans or found in nature, tiny or huge, falls into one of three categories: solids, liquids, or gases. The key features that make something “matter” are that it has mass and it occupies space.
What is Matter?
Matter is defined as anything that has mass and occupies space.
Mass: This is the amount of matter contained in an object. Imagine how much “stuff” is packed into something. Volume: This is the amount of space an object takes up. So, a book, the water you drink, and the air you breathe are all examples of matter because they have mass and take up space.
Two Common Properties of Matter:
Matter occupies space (has volume). It’s interesting to note that an object with a certain amount of matter can have more mass even if it takes up less space, and vice versa. For example:
An iron ball has more mass than a ball of cotton, even though the iron ball takes up less space than the cotton ball. This shows that the amount of matter (mass) isn’t always directly related to the amount of space it occupies.
An iron ball is heavier than a lump of cotton. Composition of Matter
Matter is made up of incredibly tiny particles that are too small to see even with a powerful microscope. These particles are called atoms and molecules.
Atoms and molecules are the building blocks of matter. Atoms: These are the smallest possible units of matter that still show all the properties of that matter. Molecules: Atoms don’t always exist alone. Sometimes, they join together to form groups called molecules. Molecules are also tiny units that show all the properties of matter and can exist independently. Key Vocabulary:
Matter: Anything that has mass and occupies space. Mass: The amount of matter present in an object.
Understanding Forms of Energy vs. Matter
It’s a common misunderstanding to think that heat, light, and sound are forms of matter. However, this is not true!
Myth: Heat, light, and sound are forms of matter. Fact: Heat, light, and sound are forms of energy. They do not occupy space or have mass, which are the defining characteristics of matter.
STATES OF MATTER
You already know that things can be solids, liquids, or gases. These are known as the states of matter.
Matter, in all its states, is made up of tiny particles (atoms and molecules). These molecules are arranged differently in solids, liquids, and gases, and these arrangements determine their properties.
Understanding Particle Arrangement:
Intermolecular Space: This is the space found between any two adjacent molecules in a substance. Intermolecular Force of Attraction (Cohesive Force): This is the force that pulls two neighboring molecules towards each other. Think of it as a tiny magnet pulling them together.
Molecules have space and attractive forces between them. The Relationship between Space and Force:
The strength of the intermolecular force of attraction depends directly on the intermolecular space.
Greater Intermolecular Space → Lesser Intermolecular Force of Attraction Lesser Intermolecular Space → Greater Intermolecular Force of Attraction
CHARACTERISTICS OF SOLIDS, LIQUIDS, AND GASES
Each state of matter has unique features based on how its molecules are arranged and how strongly they attract each other.
Solids
Molecular Arrangement: Molecules in solids are packed very closely together. Intermolecular Space: They have very little space between their molecules.
Molecules in a solid are tightly packed. Intermolecular Force of Attraction: Because the space is so small, the force of attraction between molecules is very strong. Movement: Molecules cannot move freely; they can only vibrate in their fixed positions. Shape and Volume: Solids have a fixed shape and a fixed volume. They do not easily change their shape. Compressibility: They cannot be compressed easily (meaning you can’t squeeze them into a smaller space). Changing Shape: The shape of solids can only be changed by applying a strong force, like cutting, bending, hammering, or dropping them. Flow: Solids do not flow. Containers: They do not need a container to hold them, as they keep their own shape. Examples: Chairs, computers, ice, blackboards. Reason Corner: Why is it easier to break a piece of coal than a piece of iron?
It’s easier to break a piece of coal than a piece of iron because the intermolecular forces of attraction in coal are weaker than those in iron. Iron has very strong intermolecular forces, making it much harder to break apart its molecules compared to coal.
Liquids
Molecular Arrangement: Molecules in liquids are less closely packed than in solids. Intermolecular Space: They have more space between their molecules compared to solids.
Molecules in a liquid are less tightly packed. Intermolecular Force of Attraction: The force of attraction between molecules in a liquid is not as strong as in solids, but it’s stronger than in gases. Movement: Molecules can move past each other. Shape and Volume: Liquids have a fixed volume but no fixed shape. They take the shape of the container they are in. Compressibility: They can be compressed to a certain extent, but not easily like gases. Flow: Because of weaker intermolecular forces, liquids can flow and be poured. Containers: Liquids need a container to hold them. Examples: Water, milk, juice, coffee.
Gases
Molecular Arrangement: Molecules in gases are very loosely arranged. Intermolecular Space: They have very large spaces between their molecules.
Molecules in a gas are spread far apart. Intermolecular Force of Attraction: The force of attraction between molecules in a gas is almost negligible (so weak that it barely exists). Movement: Molecules can move freely and randomly in all directions. Shape and Volume: Gases do not have a fixed shape or volume. They spread out to fill the entire space available in their container. Compressibility: Because of the large intermolecular spaces, gases can be compressed easily. Flow: Gases can flow in all directions. Containers: Gases need a closed container to hold them, otherwise they will escape. Examples: Oxygen, nitrogen, carbon dioxide.
Summary of Distinguishing Properties
Here is a table summarizing the key differences between solids, liquids, and gases:
Beyond the Three States: Plasma
Sometimes, when a gas is heated to an extremely high temperature, it changes into a fourth state of matter called plasma. Plasma is found in lightning, stars, and neon signs!
Special Concepts and Connections
Diffusion
Diffusion is the spreading out and mixing of one substance with another substance. This happens because the particles of both substances are constantly moving.
How it Works: Particles move from an area where they are more concentrated to an area where they are less concentrated, causing them to spread out and mix. Where it Occurs: Diffusion happens in all states of matter: solids, liquids, and gases. Solids: Diffusion in solids is extremely slow because their molecules are tightly packed and cannot move much. Liquids and Gases: Diffusion happens easily in liquids and gases because their molecules have more intermolecular space and can move randomly. Gas into Liquid: Oxygen dissolving into water bodies allows aquatic animals to breathe. Gas into Gas: The aroma of food spreading through the air and reaching your nose. Factors Affecting Diffusion: Temperature: Higher the temperature, faster the rate of diffusion. This is because higher temperatures give particles more energy to move.
Ink diffusing in water at different temperatures.
Environmental Connection: Air Pollution
Smoke from vehicles is a gas that spreads throughout the atmosphere, causing air pollution. Some places, like Matheran in Maharashtra (Asia’s only automobile-free hill station), have very little air pollution because there are no vehicles. This highlights how gases (pollutants) move and spread. Reducing air pollution involves careful planning towards resource efficiency and adapting to climate change, aligning with global goals for sustainable cities.
United Nations’ Sustainable Development Goal 11: Sustainable Cities and Communities.
Demonstrating Gas Properties: Air Occupies Space
You can see that air, a gas, occupies space.
Observation: If you try to inflate a balloon inside a plastic bottle (with the balloon’s opening stretched over the bottle’s top), it won’t inflate as much as it would outside the bottle. Reason: The air already present inside the bottle occupies all the space, preventing the balloon from expanding fully. This demonstrates that gases, like air, take up space.
Experiment showing air occupies space.
Science and Scientists: Democritus
The idea that matter is made of small particles is very old! Democritus (460 - 370 BCE), a famous Greek philosopher, proposed this theory.
Matter is built of small particles. These particles cannot be divided into anything smaller. There is empty space between these particles. These particles are in constant motion.
Bust of Democritus.
Integrating Knowledge: Elements and Their States
Elements are the basic building blocks of matter, and they can exist as solids, liquids, or gases at room temperature.
Here are some examples of elements and their common states:
CONCEPT RECALL: Chapter Summary
Here’s a big picture view of everything you’ve learned about matter and its states:
Self Study
An iron ball is heavier than a lump of cotton.
Atoms and molecules are the building blocks of matter.
Molecules have space and attractive forces between them.
Ink diffusing in water at different temperatures.
United Nations’ Sustainable Development Goal 11: Sustainable Cities and Communities.
Experiment showing air occupies space.
Bust of Democritus.
