NCERT Revision notes for class 6 Science Sorting Materials into Groups

Download PDF

Materials

The things that we see around us such as table, chair, rubber, box etc are called materials.

The materials are classified in the following categories:

Based on appearance, materials can be classified into two categories

Shiny: The materials that have shiny surface are called shiny materials. For example: gold and silver
Dull: The materials, which have no shine on their surface, are called dull materials. For example: rubber and wood

Based on hardness, the materials can be classified into two categories

Hard: The materials, which have hard surface, are called hard materials. These materials cannot be compressed easily. For example: wood, iron and brick.
Soft: Materials which are soft to touch are called soft materials. These materials can be compressed easily. For example: sponge and cotton.

Soluble: Materials that easily dissolved in water are called soluble substance. For example: sugar and salt.
Insoluble: Materials that do not easily dissolved in water are called insoluble substance. For example: sand and chalk powder.

Float: Materials that float on water are called floating materials. For example: leaves and wood log.
Sink: Materials that sink or submerged in water are called sinking substance. For example: pebbles and iron nail.

Based on transparency the materials can be classified into the following categories:

Transparent: The materials that allows the light to pass through it are called transparent. We can see clearer through these materials. For example: window glass.
Translucent: The objects through which we cannot see clearly are called translucent materials. It allows less light to pass through it. For example: polythene.
Opaque: The objects that do not allow the light to pass through them and form shadow are called opaque materials. We cannot see through them. For example: Wooden block.