⚡ Quick Revision: Quick Definitions & Core Terms
Matter = Has Mass + Occupies Space
- Symbols: Mass = amount of matter; Space = volume occupied
- SI Unit: Mass = kilogram (kg); Volume = cubic metre (m3)
For matter-based questions, first identify the property asked: mass uses g or kg, volume uses mL, L, cm3 or m3.
Matter has mass and occupies space vs Non-matter does not have mass or volume, such as light and sound.
M = M + S
Matter = Mass + Space.
| Term | Quick Meaning | Example |
|---|---|---|
| Matter | 🔥 Has mass and occupies space | Air, water, book |
| Mass | Amount of matter | Mass of a stone |
| Volume | Space occupied | Water in a bottle |
| Non-matter | No mass and no volume | Light, sound |
Air is matter because it has mass and occupies space, even though we cannot see it.
Matter = Mass + Space
- Use: To identify whether something is matter.
- Units: Mass = kg, Volume = m3 or L.
- Matter has mass and occupies space.
- Mass means amount of matter.
- Volume means space occupied.
- Air is matter even though it is invisible.
- Light and sound are not matter.
⚡ Quick Revision: Properties of Matter
Even invisible substances like air are matter because they have mass and occupy space.
Volume = Space Occupied
- Symbols: Volume shows how much space an object takes.
- SI Unit: cubic metre (m3); common units: L, mL, cm3
If the question says "how heavy", think mass. If it says "how much space", think volume.
Mass is amount of matter vs Volume is space occupied by matter.
MASS + SPACE = MATTER
If both are present, the object is matter.
| Property | Quick Meaning | High-Yield Example |
|---|---|---|
| Mass | Amount of matter | 🔥 Book has mass |
| Volume | Space occupied | Water occupies bottle space |
| Air | Invisible matter | Inflated balloon has air |
| Shape | May be fixed or changing | Solid has fixed shape |
Do not say only visible things are matter. Air is invisible but still matter.
Matter Check = Mass + Volume
- Use: Quick test to identify matter.
- Units: Mass = kg or g; Volume = m3, cm3, L or mL.
- Matter has mass.
- Matter occupies space.
- Volume means space occupied.
- Air is invisible matter.
- Mass and volume are the two main checks for matter.
⚡ Quick Revision: States of Matter
Matter commonly exists in three states: solid, liquid and gas.
State = Shape + Volume
- Symbols: Shape = fixed or not fixed; Volume = fixed or not fixed
- SI Unit: Volume = cubic metre (m3); common units: L, mL, cm3
| State | Shape | Volume | Example |
|---|---|---|---|
| Solid | Fixed | Fixed | 🔥 Ice, stone, book |
| Liquid | Not fixed | Fixed | Water, milk, oil |
| Gas | Not fixed | Not fixed | Air, oxygen, steam |
For liquids, remember: volume is commonly measured in litre (L) or millilitre (mL).
Liquid has fixed volume vs Gas does not have fixed volume.
S-L-G = Strong-Little-Free
Solid particles are tightly packed, liquid particles move a little, gas particles move freely.
Do not write that liquids have no volume. Liquids have fixed volume but take the shape of the container.
State Check = Shape + Volume
- Use: To identify solid, liquid or gas quickly.
- Units: Volume = m3, cm3, L or mL.
- Solid has fixed shape and fixed volume.
- Liquid has fixed volume but no fixed shape.
- Gas has no fixed shape and no fixed volume.
- Liquids take the shape of their container.
- Gases spread to fill available space.
⚡ Quick Revision: Change of State
Heating usually changes solid to liquid to gas; cooling usually changes gas to liquid to solid.
Change of State = Heating or Cooling
- Symbols: Heating adds heat; Cooling removes heat
- SI Unit: Temperature = kelvin (K); common unit = degree Celsius (°C)
For temperature-based questions, write the unit clearly: °C for school-level temperature and K for SI unit.
| Change | Direction | Cause | Example |
|---|---|---|---|
| Melting | Solid to liquid | Heating | 🔥 Ice to water |
| Freezing | Liquid to solid | Cooling | Water to ice |
| Evaporation | Liquid to vapour | Heat from surroundings | Wet clothes drying |
| Condensation | Vapour to liquid | Cooling | Water drops on cold glass |
Evaporation is slow and occurs from the surface vs Boiling is fast and occurs throughout the liquid.
M-F-E-C
Melting, Freezing, Evaporation, Condensation.
Do not write evaporation and boiling as exactly the same process. Both form vapour, but their speed and place of occurrence are different.
Heating: Solid → Liquid → Gas
Cooling: Gas → Liquid → Solid
- Use: Quick recall for change of state questions.
- Unit: Temperature = K or °C.
- Melting changes solid to liquid.
- Freezing changes liquid to solid.
- Evaporation changes liquid to vapour.
- Condensation changes vapour to liquid.
- Heating and cooling cause change of state.
⚡ Quick Revision: Formulae, Units & Numerical Readiness
Always write the final answer with the correct unit. A number without unit can lose marks.
Volume = Length x Breadth x Height
- Symbols: L = length, B = breadth, H = height
- SI Unit: cubic metre (m3); common unit = cm3
Matter = Mass + Volume
- Symbols: Mass = amount of matter; Volume = space occupied
- SI Unit: Mass = kg; Volume = m3
Step 1: Write formula. Step 2: Substitute values with units. Step 3: Calculate and write final unit.
1 kg = 1000 g, 1 L = 1000 mL, and 1 mL = 1 cm3 for water-like liquids at this level.
kg and g measure mass vs L and mL measure liquid volume.
| Quantity | Meaning | Units |
|---|---|---|
| Mass | Amount of matter | 🔥 kg, g |
| Volume | Space occupied | m3, cm3, L, mL |
| Length | One side measurement | m, cm |
| Temperature | Hotness or coldness | K, °C |
M-KG, V-L
Mass goes with kg or g; Volume goes with L, mL, cm3 or m3.
Do not write volume answer in kg or mass answer in litre. Units must match the physical quantity.
Volume of Cuboid = L x B x H
- Use: To find volume of regular box-shaped solids.
- Unit: cm3 or m3.
- Mass is measured in kg or g.
- Volume is measured in m3, cm3, L or mL.
- Volume of cuboid = L x B x H.
- 1 kg = 1000 g and 1 L = 1000 mL.
- Always write the final answer with unit.
⚡ Quick Revision: Final Recall Sheet & Exam Readiness
Matter is anything that has mass and occupies space. This is the most important definition of the chapter.
Matter = Mass + Space
Volume of Cuboid = L x B x H
- Symbols: L = length, B = breadth, H = height
- SI Units: Mass = kg; Volume = m3
Before solving, check units: length in same unit, mass in kg or g, volume in cm3, m3, L or mL.
| Quick Topic | Must Remember | Example |
|---|---|---|
| Matter | 🔥 Has mass and occupies space | Air, water, stone |
| Solid | Fixed shape and fixed volume | Ice, book |
| Liquid | No fixed shape, fixed volume | Water, milk |
| Gas | No fixed shape, no fixed volume | Air, steam |
| Change of State | Caused by heating or cooling | Ice melts |
Evaporation is slow surface change vs Boiling is fast change throughout the liquid.
Do not forget units in numericals. Write cm3, m3, L, mL, g or kg correctly.
M-S-V-C
Matter, States, Volume, Change of state.
Matter → Mass + Space → Solid / Liquid / Gas → Heating or Cooling → Change of State
Volume = Length x Breadth x Height
- Use: Regular cuboid-shaped objects.
- Unit: cm3 or m3.
- Matter = mass + space.
- Air is matter because it occupies space and has mass.
- Solid has fixed shape and fixed volume.
- Liquid has fixed volume but no fixed shape.
- Heating and cooling can change the state of matter.