Metals have shiny surfaces in their pure state. This property is called lustre. Ornaments are made of lustrous metals so that they can shine.

Properties: 1 Mark each
The properties of the solid state are as follows:
Any two:
1. Solids have definite shape and volume.
2. They cannot be compressed too much.
3. The particles are closely packed.
4. They cannot flow.

Iron is the odd one out since it is a hard material and the rest are soft.

Process: 1 Mark
Property name: 1 Mark
When sugar is mixed with water, it will dissolve.
This property of sugar is called solubility.

Determination: 1 Mark
Examples: 1 Mark
Materials which are light in weight usually float in water while the materials which are heavy in weight sink in water. So a major factor which determines floatation or sinking is weight.
Example of objects which float in water are: paper, plastic balls, etc
Example of objects which sink in water are: iron, stones, etc

Classifications: 1 Mark each
On the basis of the amount of light they let through them, materials are classified into three: transparent, translucent and opaque.
Transparent materials are those which let light pass through them completely. Examples include glass and water.
Translucent materials only partially let light pass through them. The rest of the light is reflected away. Examples: frosted glass, tracing paper.
Opaque materials do not let any light pass through them. All the light is reflected from the material. Examples: Wood, iron, etc.

Types of conductivity: 1 Mark
Conductivities: 2 Marks each
There are two types of conductivities - heat and electricity.
Based on conduction of heat, materials can be classified into either good or bad conductors.
Materials that allow heat to pass through them are called good conductors of heat.
Example: Metals are usually good conductors of heat.
Materials that do not allow heat to pass through them are called bad conductors of heat.
Example: Plastic, air.
Based on conduction of electricity, materials can be classified into either good or bad conductors.
Materials that let electricity pass through them are called good conductors of electricity.
Example: Metals are generally good conductors of electricity.
Materials that do not let electricity pass through them are called insulators or bad conductors of electricity.
Example: Plastic, Wood, air.

Properties: 1 Mark each
Properties of gases:
1. Gases have no definite shape or volume.
2. Particles of gases are very loosely packed.
3. Gases are highly compressible.

Points: 1 Mark each
1. When salt is mixed with water, it dissolves in the water and disappears.
2. This property of dissolution of salt in water is called solubility.
3. If chalk powder was used instead of salt, it will not dissolve but will settle down as sediment after a while.
4. This is because chalk powder is insoluble in water.
5. Based on solubility, materials can be classified as either soluble or insoluble.