Matter is anything that has mass and occupies space. Everything around us—solids, liquids, and gases—is made of matter. Matter can change its state with variations in temperature and pressure.
States of Matter
Solid
Fixed shape and volume.
Particles are closely packed and vibrate in place.
Example: Ice, wood, iron.
Liquid
Fixed volume but takes the shape of its container.
Particles are close but can move past each other.
Example: Water, oil, milk.
Gas
Neither fixed shape nor volume.
Particles are far apart and move freely.
Example: Oxygen, nitrogen, carbon dioxide.
Properties of Matter
Property
Solid
Liquid
Gas
Shape
Fixed
Takes container’s shape
No fixed shape
Volume
Fixed
Fixed
No fixed volume
Compressibility
Low
Slight
High
Particle Movement
Vibrate
Slide past each other
Move freely
Changes in State of Matter
Melting: Solid → Liquid (e.g., ice → water)
Freezing: Liquid → Solid (e.g., water → ice)
Evaporation: Liquid → Gas (e.g., water → vapor)
Condensation: Gas → Liquid (e.g., water vapor → dew)
Sublimation: Solid → Gas directly (e.g., camphor, dry ice)
Deposition: Gas → Solid directly (e.g., frost formation)
Effect of Temperature and Pressure
Increasing temperature can change solids to liquids and liquids to gases.
Increasing pressure can compress gases or influence melting/boiling points.
Example: Water boils at lower temperature at high altitudes due to low pressure.
Diffusion
The spreading of particles from high concentration to low concentration.
Occurs in liquids and gases, very slowly in solids.
Example: Perfume spreading in a room, sugar dissolving in water.
Quick Short Q&A
Question
Short Answer
What is matter?
Anything that has mass and occupies space.
Name the three states of matter.
Solid, Liquid, Gas.
Example of solid, liquid, gas?
Ice, water, oxygen.
Which state has fixed volume but no fixed shape?
Liquid
Which state is highly compressible?
Gas
Melting and freezing definitions?
Melting: Solid→Liquid, Freezing: Liquid→Solid
Example of sublimation?
Camphor, dry ice
What is diffusion?
Spreading of particles from high to low concentration
Effect of temperature on states?
Increases temperature → solids melt, liquids evaporate