Introduction
- We can sort or classify materials we come across into many groups based on their appearances, the things from which they are made , their nature , solubility in water, hardness or softness etc.
- In this chapter we will majorly focus on sorting of substances on the basis of their appearance(Lustre) , Hardness or Softness, and solubility in water.
S.No. | Objects | Materials from which they are made. |
1. | Book | paper |
2. | Tumbler | Wood |
3. | Chair | Wood |
4. | Toy | Plastic/ Metal |
5. | Shoes | Leather |
6. | Table | Wood/ Plastic |
7. | Pencil | Wood |
8. | Utensils | Metal |
Substance with Lustre and without Lustre
Those materials which shine when they are cut further are said to be with lustre and those which donot shine at all are called without lustre. Following materials are available in every home and surroundings:
Utensils, plastic, Polished table, stones, Pencil, eraser, Leather shoes, TV, Washing Machine, Gas stove, Tiles, Marbles, Sand, Clothes, Wallet, Cloth Bag, Gold Ornaments , wood, chalk, paper, aluminium sheet, Silver Ornaments, etc.
We can divide or sort them into two groups as following: {Activity 3}
S.No. | With Lustre | Without Lustre |
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. | Utensils Polished Table Leather Shoes TV Washing Machine Gas stove Tiles Marbles Wallet Gold Ornaments Silver Ornaments | Plastic Stones eraser Sand Clothes Wood Chalk Paper Aluminium sheet Cloth Bag, Pencil |
Sorting Materials into Hard and Soft
Sorting Materials Into Hard and soft materials.
Those materials which are easily scratched and compressed are soft while those which cannot be compressed or scratched are hard materials.
Following materials are available in every home and surroundings:
Utensils, plastic, Polished table, stones, Pencil, eraser, Leather shoes, TV, Washing Machine, Gas stove, Tiles, Marbles, Sand, Clothes, Wallet, Cloth Bag, Gold Ornaments , wood, chalk, paper, aluminum sheet, Silver Ornaments, Cotton etc.
S.No. | Hard | Soft |
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. | Utensils Table shoes TV Washing Machine Gas stove Tiles Marbles Aluminum sheet Gold Ornaments Silver Ornaments Pencil Stones Sand Plastic | Wallet eraser Clothes Wood Chalk Paper Bag, Cotton
|
Sorting into Soluble and Insoluble Substances
Soluble and Insoluble Substances.
We come across many materials in our surroundings which either dissolve in water or don’t dissolve in water. Those substances which dissolve in water are called soluble substances, while those substances which don’t dissolve in water are called insoluble substances. How we can determine the solubility and insolubility of a material is very easy to determine. Put the thing to be tested in water and stir it for some time. If the thing/ object dissolves and gets mixed to the water, it is soluble otherwise it is not soluble.
Activity 4-
Sort the following materials into soluble and insoluble substances-
Sugar, Salt, Chalk powder, Sand , Saw dust, Milk, Oil, Ink.Plastic, Stone
S.No. | Soluble | Insoluble |
1. 2. 3. 4. 5.
| Sugar, Salt, Chalk powder, Milk, Ink
| Sand , Saw dust, Oil, Plastic, Stone
|
Fill in the Blanks
- Materials that do not allow light to pass through them are called opaque substances.
- Dried leaves fallen from tree float in the pond.
- Metals have a shiny appearance called as lustre.
- Materials which can be pressed easily are called soft materials.
- Copper and gold are hard and shiny metals.
- Sugar and salt are soluble in water.
- Sand and oil are insoluble in water.
- Glass is transparent while iron is opaque.
- Shoes are made up of leather or plastic or cloth.
- A stone sinks in pond.