Definitions [5]
Define matter
Anything that has mass and occupies space is called matter.
Define interconversion of states of matter.
The process by which matter changes from one state to another and back to the original state, without any change in its chemical composition.
Define the term relative density of a substance.
RELATIVE DENSITY: “is the ratio of the density of a substance to the density of water at 4° C.”
Or
RELATIVE DENSITY “is the ratio of the mass of the substance to the mass of an equal volume of water at 4° C.”
Define the term Density of a substance.
Density of a substance is defined as “Mass per Unit volume”.
Density [d]=`"mass of the substance"/"volume of the substance"`
d=`m/v`
What is the unit of relative density?
UNIT OF RELATIVE DENSITY: No units since it is a pure ratio.
Key Points
| Property | Solid | Liquid | Gas |
|---|---|---|---|
| Mean molecular separation | ~3–5 Å | ~3–10 Å | >5 Å |
| Particle arrangement | Tightly packed, regular | Loosely packed, irregular | Highly irregular |
| Particle movement | Fixed positions, cannot move freely | Moves a small distance within liquid | Continuous random motion |
| Shape & volume | Definite shape and volume | Takes shape of container, definite volume | Takes shape and volume of container |
| Intermolecular space | Very small | Moderate | Large |
| Effect of temperature | Small volume change | Moderate volume change | Significant volume change |
| Compressibility | Practically incompressible | Slightly compressible | Highly compressible |
| Example | A piece of iron | Water, spirit, oil | Air |
Concepts [15]
- Various uses of changes in physical state
- States of Matter
- The Solid State
- The Liquid State
- The Gaseous State
- Fibre
- Plant Fibres: Cotton
- Plant Fibre: Jute Fibre
- Fibre to Yarn to Fabric
- Man-made Fibre: Synthetic Fibres
- Grain
- Household Goods
- Buoyancy Force (Upthrust Force)
- Water - a Universal Solvent
- Density of the Fluid
