Chapter 1: Matter in Our Surroundings
Matter: Anything that occupies space and has mass is called matter.
Properties of matter: mass, volume, inertia.
States of matter: solid, liquid, gas.
Mass: Amount of matter present in a body.
Volume: Space occupied by a body.
Density: mass/volume.
Inertia: Tendency of a body to resist change in its state of motion.
Solid: Fixed shape and volume, particles closely packed, strong intermolecular forces.
Liquid: Fixed volume, shape changes according to container, particles close but can move.
Gas: Neither fixed shape nor volume, particles far apart, weak intermolecular forces.
Change of state:
- Melting, Freezing, Evaporation, Condensation, Sublimation.
- Latent Heat: Energy absorbed or released during a change of state without temperature change.
- Latent heat of fusion, vaporization.
Diffusion: Spontaneous mixing of particles of two substances due to random motion.
Diffusion in solids, liquids, gases.
Factors affecting diffusion: temperature, particle mass, medium.
Examples: Perfume spreading, sugar in water, oxygen exchange in lungs.
Pure Substances:
- Elements: Cannot be broken down chemically. Eg: Oxygen, Iron.
- Compounds: Can be broken down chemically. Eg: Water (H2O), Carbon dioxide (CO2).
Mixtures:
- Homogeneous: Uniform composition. Eg: Sugar solution.
- Heterogeneous: Non-uniform composition. Eg: Sand in water.
Numerical Examples:
1. Calculate the density of a substance of mass 50 g and volume 25 cm^3.
Solution: Density = mass/volume = 50/25 = 2 g/cm^3
2. A block of ice of mass 200 g melts completely. Calculate heat absorbed. (Latent heat of fusion of
ice = 334 J/g)
Solution: Heat = mass * Lf = 200*334 = 66800 J
Matter: Anything that occupies space and has mass is called matter.
Properties of matter: mass, volume, inertia.
States of matter: solid, liquid, gas.
Mass: Amount of matter present in a body.
Volume: Space occupied by a body.
Density: mass/volume.
Inertia: Tendency of a body to resist change in its state of motion.
Solid: Fixed shape and volume, particles closely packed, strong intermolecular forces.
Liquid: Fixed volume, shape changes according to container, particles close but can move.
Gas: Neither fixed shape nor volume, particles far apart, weak intermolecular forces.
Change of state:
- Melting, Freezing, Evaporation, Condensation, Sublimation.
- Latent Heat: Energy absorbed or released during a change of state without temperature change.
- Latent heat of fusion, vaporization.
Diffusion: Spontaneous mixing of particles of two substances due to random motion.
Diffusion in solids, liquids, gases.
Factors affecting diffusion: temperature, particle mass, medium.
Examples: Perfume spreading, sugar in water, oxygen exchange in lungs.
Pure Substances:
- Elements: Cannot be broken down chemically. Eg: Oxygen, Iron.
- Compounds: Can be broken down chemically. Eg: Water (H2O), Carbon dioxide (CO2).
Mixtures:
- Homogeneous: Uniform composition. Eg: Sugar solution.
- Heterogeneous: Non-uniform composition. Eg: Sand in water.
Numerical Examples:
1. Calculate the density of a substance of mass 50 g and volume 25 cm^3.
Solution: Density = mass/volume = 50/25 = 2 g/cm^3
2. A block of ice of mass 200 g melts completely. Calculate heat absorbed. (Latent heat of fusion of
ice = 334 J/g)
Solution: Heat = mass * Lf = 200*334 = 66800 J
