Matter
Q: What is matter?
A: Matter is anything that has mass and occupies space.Q: Name the three states of matter.
A: Solid, liquid, and gas.Q: Give two examples of each state of matter.
A: Solid – stone, wood; Liquid – water, milk; Gas – air, oxygen.Q: What is mass?
A: Mass is the amount of matter in an object.Q: What is volume?
A: Volume is the amount of space an object occupies.Q: Name two properties of solids.
A: Fixed shape and fixed volume.Q: What property of liquids makes them take the shape of the container?
A: Liquids have no fixed shape.Q: Do gases have fixed volume?
A: No, gases do not have fixed volume.Q: What happens to the particles of matter when it is heated?
A: They move faster and may change state.Q: Define condensation.
A: The process of gas changing into a liquid on cooling.Q: What is evaporation?
A: The process of a liquid changing into gas on heating.Q: What is freezing?
A: The process of a liquid changing into solid on cooling.Q: Can matter be created or destroyed?
A: No, it only changes form.Q: What is a physical change?
A: A change in which no new substance is formed.Q: What is a chemical change?
A: A change in which a new substance is formed.Q: Give one example of a physical change.
A: Melting of ice.Q: Give one example of a chemical change.
A: Burning of paper.Q: What are atoms?
A: Atoms are the smallest unit of matter.Q: What are molecules?
A: Molecules are groups of two or more atoms bonded together.Q: What is diffusion?
A: The mixing of particles of one substance with another.Q: Which state of matter is most compressible?
A: Gas.Q: Which state of matter has the strongest intermolecular force?
A: Solid.Q: Which state of matter flows easily?
A: Liquid.Q: Why does ice float on water?
A: Because ice is less dense than water.Q: What is sublimation?
A: The change of solid directly into gas without becoming liquid.
🔸 Subjective Type Questions
Q: Explain the characteristics of solids, liquids, and gases.
A:
Solids: Fixed shape and volume, particles are tightly packed.
Liquids: No fixed shape, fixed volume, particles are less tightly packed.
Gases: No fixed shape or volume, particles are far apart and move freely.
Q: How does temperature affect the state of matter?
A: On heating, solids melt into liquids, and liquids evaporate into gases. On cooling, gases condense into liquids, and liquids freeze into solids.Q: Describe the particle arrangement in solids, liquids, and gases.
A:
Solids: Closely packed, fixed position.
Liquids: Loosely packed, can slide past each other.
Gases: Very loosely packed, move freely.
Q: Explain the process of water changing states in the water cycle.
A: Water evaporates from surfaces (evaporation), forms clouds (condensation), and falls as rain (precipitation), which may freeze (freezing) or remain liquid.Q: Differentiate between physical and chemical changes with two examples each.
A:
Physical Change: No new substance, e.g., melting ice, breaking glass.
Chemical Change: New substance formed, e.g., rusting of iron, burning wood.
Q: What are the uses of knowing different states of matter?
A: Understanding matter helps in cooking, manufacturing, transport of gases and liquids, and storage of materials.Q: How does pressure affect gases?
A: Increasing pressure compresses gases as their particles come closer.Q: Describe an activity to show that air has mass.
A: Weigh two balloons — one inflated and one deflated. The inflated balloon will be heavier, proving air has mass.Q: What changes occur when a candle burns?
A: Melting wax is a physical change; burning wick is a chemical change.Q: How does matter change from solid to gas directly? Give examples.
A: Through sublimation. Examples: camphor, dry ice.Q: Why do we see water droplets outside a cold glass of water?
A: Water vapor in air condenses on the cold surface of the glass.Q: How do we know air is a matter?
A: Air has mass, occupies space, and can exert pressure.Q: What is the role of heat in changing states of matter?
A: Heat provides energy for particles to overcome their attraction and change state.Q: Write a short note on intermolecular forces.
A: These are the forces of attraction between molecules. Strongest in solids, weaker in liquids, weakest in gases.Q: What is the importance of the study of matter in daily life?
A: It helps us understand and use different materials effectively for cooking, cleaning, building, etc.Q: Why do gases spread faster than liquids?
A: Gas particles are far apart and move freely, while liquid particles are closer and move slower.Q: Why is it easier to compress gas than liquid?
A: Because gas particles are far apart and can be pushed closer.Q: State three differences between solids and liquids.
A: Solids have fixed shape and volume, particles are tightly packed; Liquids have no fixed shape, fixed volume, particles are less tightly packed.Q: Describe the role of evaporation in cooling.
A: When liquid evaporates, it takes heat from the surroundings, causing cooling.Q: Why is water called a universal solvent?
A: Because it can dissolve a wide variety of substances.Q: Explain how rusting is a chemical change.
A: Iron reacts with oxygen and water to form a new substance – rust.Q: Differentiate between reversible and irreversible changes with examples.
A: Reversible: can be undone (melting), Irreversible: cannot be undone (burning).Q: How does diffusion help in our daily life?
A: It helps in smelling food from a distance, mixing of gases in air, etc.Q: Why are solids not easily compressible?
A: Their particles are tightly packed with little space between them.Q: How is boiling different from evaporation?
A: Boiling occurs at a fixed temperature throughout the liquid, while evaporation occurs at all temperatures from the surface.