⚡ Quick Revision: Matter at a Glance
- Air, water, stone, book and milk are examples of matter.
- Light, sound and shadow are not matter.
- Matter must have both mass and volume.
Makeup: If something has mass and takes up space, it is matter.
Object → Has Mass? + Occupies Space? → Matter
Observation: A stone has mass and occupies space, so it is matter.
Mass is amount of matter vs Volume is space occupied by matter.
Do not write that sound is matter. Sound does not have mass and does not occupy space.
MASS
Matter Always Shows Space.
| Example | Matter / Not Matter | Reason |
|---|---|---|
| Air | Matter | Has mass and occupies space |
| Water | Matter | Has mass and volume |
| Sound | Not matter | No mass, no volume 🔥 |
| Book | Matter | Occupies space |
- Matter has mass and occupies space.
- Mass means amount of matter.
- Volume means space occupied.
- Air and water are matter.
- Sound and shadow are not matter.
⚡ Quick Revision: States of Matter
- Solids have fixed shape and fixed volume.
- Liquids take the shape of the container but have fixed volume.
- Gases fill the entire container.
Makeup: To identify a state, check whether shape and volume are fixed or not fixed.
Ice → Water → Water Vapour
Observation: The same substance can exist as solid, liquid and gas.
Liquid has fixed volume but no fixed shape vs Gas has neither fixed shape nor fixed volume.
Do not write that liquids have fixed shape. Liquids take the shape of the container.
S-L-G
Solid stays, Liquid levels, Gas goes everywhere.
| State | Shape | Volume | Example |
|---|---|---|---|
| Solid | Fixed | Fixed | Stone, ice |
| Liquid | Not fixed | Fixed | Water, milk |
| Gas | Not fixed | Not fixed | Air, steam 🔥 |
- Matter exists mainly as solid, liquid and gas.
- Solid has fixed shape and fixed volume.
- Liquid has fixed volume but no fixed shape.
- Gas has no fixed shape and no fixed volume.
- Water can exist as ice, water and water vapour.
⚡ Quick Revision: Properties of Solids, Liquids and Gases
- Solids are rigid because particles are closely packed.
- Liquids flow because particles can slide past one another.
- Gases are highly compressible because particles are far apart.
Makeup: Particle spacing is least in solids, more in liquids and maximum in gases.
Gas + Pressure → Smaller Space
Observation: Gas can be compressed because its particles have large spaces between them.
Fluidity means ability to flow vs Compressibility means ability to be pressed into smaller space.
Do not write that only liquids are fluids. Gases are also fluids because they can flow.
S-L-G = Tight, Loose, Gone
Solid particles are tight, Liquid particles are loose, Gas particles are far gone.
| Property | Solid | Liquid | Gas |
|---|---|---|---|
| Rigidity | High | Low | Very low |
| Fluidity | No | Yes | Yes 🔥 |
| Compressibility | Very low | Low | High |
| Particle Space | Least | More | Maximum |
- Solids are rigid and do not flow.
- Liquids and gases are fluids.
- Gases are highly compressible.
- Particles are closest in solids.
- Particles are farthest apart in gases.
⚡ Quick Revision: Change of State
- Heating usually changes solid to liquid and liquid to gas.
- Cooling usually changes gas to liquid and liquid to solid.
- Change of state is usually a physical change.
Makeup: Heat increases particle movement and changes matter to a less fixed state.
Makeup: Cooling decreases particle movement and changes matter to a more fixed state.
Ice + Heat → Water + Heat → Water Vapour
Observation: Ice melts into water and water changes into vapour on heating.
Evaporation is slow surface change vs Boiling is fast change throughout the liquid.
Do not write that melting forms a new substance. Melting only changes the state of the substance.
M-F-E-C
Melting heats solid, Freezing cools liquid, Evaporation makes vapour, Condensation makes liquid.
| Change | Direction | Cause | Example |
|---|---|---|---|
| Melting | Solid → Liquid | Heating | Ice to water |
| Freezing | Liquid → Solid | Cooling | Water to ice |
| Evaporation | Liquid → Vapour | Heating | Wet clothes drying 🔥 |
| Condensation | Vapour → Liquid | Cooling | Water drops on cold glass |
- Melting changes solid into liquid.
- Freezing changes liquid into solid.
- Evaporation changes liquid into vapour.
- Condensation changes vapour into liquid.
- Change of state is usually a physical change.
⚡ Quick Revision: Final Exam Recall Sheet
- 🔥 Matter has mass and occupies space.
- 🔥 Solids have fixed shape and fixed volume.
- 🔥 Change of state is usually a physical change.
Makeup: If it has mass and occupies space, it is matter.
Makeup: Heating increases particle movement and changes matter to a less fixed state.
Ice + Heat → Water + Heat → Water Vapour
Observation: Matter changes state on heating, but the substance may remain the same.
Physical change usually forms no new substance vs Chemical change forms a new substance.
Do not write that gases have fixed volume. Gases spread and fill the entire container.
MASS + S-L-G
MASS: Matter Always Shows Space. S-L-G: Solid stays, Liquid levels, Gas goes everywhere.
| Concept | Quick Recall | Exam Trap |
|---|---|---|
| Matter | Mass + space | Sound is not matter 🔥 |
| Solid | Fixed shape + fixed volume | Particles closely packed |
| Liquid | No fixed shape + fixed volume | Takes container shape |
| Gas | No fixed shape + no fixed volume | Highly compressible |
| Change of State | Physical change | No new substance usually formed |
Matter → Has Mass + Space → Solid / Liquid / Gas → Changes State on Heating or Cooling
- Matter has mass and occupies space.
- Mass means amount of matter.
- Volume means space occupied.
- Solids, liquids and gases are states of matter.
- Heating and cooling can change the state of matter.