Materials that are attracted to magnets are called magnetic materials. Example - Iron.

Classification: 1 Mark each
Materials can be classified into two based on their hardness - hard materials and soft materials. 
Materials that can be compressed or scratched easily are called soft materials.
Example: Cotton, Sponge.
Materials that are difficult to compress are called hard.
Example: Iron and most of the other metals.

States and examples: 1 Mark each
The three states of matter are gaseous, liquid and solid.
Example of gaseous state: Oxygen.
Example of liquid state: Water.
Example of solid state: Iron.

Grouping materials is done to make it convenient for us to study all the materials. Objects are grouped on the basis of their shapes, the materials they are made up of, and the properties of these materials. Materials can be grouped on the basis of similarities or differences in their properties.

Points: 1 Mark each
1. If a material has density less than water, it will float on water. Iron is a metal and metals have very high density because of which they cannot float on water.
2. Ships made of iron float on water because even though metals sink, the ships are constructed in such a way that the total density of the ship is less than that of water. The principle behind their floating is Archimedes' Principle.
This is how ships made of metal manage to stay afloat.

Explanation: 1 Mark each
Property name: 1 Mark
1. The oil does not mix with water which means that it is insoluble in water. Things which are soluble in water mix with it and disappear.
2. It settles on the top of the water which shows that it can float on water. Generally, materials float on water if their density is less than that of water so certainly the density of the oil was less than that of water.
3. The oil here is exhibiting insolubility.

Properties: 1 Mark each
Properties of liquid substances:
1. Liquids do not have definite shapes; they take the shape of the container but have a definite volume.
2. The particles of liquids are loosely packed than the particles in solids.
3. They can be compressed to a small extent. 

Materials: 1 Mark each
 

Materials: 1 Mark each

Classifications: 1 Mark each
Objects are grouped on the basis of properties like:
Any 5:
Lustre - lustrous, non-lustrous
Hardness - hard, soft
Transparency - transparent, translucent, opaque
Solubility - soluble, insoluble
Floatation - floating materials, sinking materials
Attraction towards magnets - magnetic, non-magnetic
Conduction of heat - good conductors, bad conductors
Conduction of electricity - good conductors, bad conductors