CIE Biology Paper-5: Specimen Questions 52 - 52 of 62
Question number: 52
Describe in Detail
Materials are classified based on their properties. Classify the given materials on the basis of properties.
Use such materials-
Wax, glass piece (with blunt edges), oil coated paper, sugar, green leaf, piece of coal, piece of wood, a coin, a piece of sponge, a container, water, spoon/glass rod, a sheet of white paper.
Given materials can be classified based on properties, such as hardness, solubility in water, floats in water, and transparency.
1-At first take the given materials one by one and observe the materials which are compressed on applying some pressure.
Observation-Materials, which were easy to press, are soft, such as wax, green leaf, sponge, etc. Materials, which were difficult to press, are hard, such as glass piece, sugar crystals, coin, and coal and wood.
2-Take a glass and fill it half with water. Add any given material and see whether it floats or sinks. Now stir it with a spoon or glass rod and check if it is soluble or insoluble. Repeat the same steps with other materials also.
Observation-Materials, which dissolved in water, are called soluble materials, such as sugar. Materials, which did not dissolve in water after stirring fora long, are called insoluble materials, such as wax, glass piece, coin, coal, wood, green leaf, sponge etc. Some materials float in water such as wax, wood and coal. Some materials sink in water, such as sugar, coin, glass piece
3-Take a strip of white paper and make a dark spot on it. Place the given materials one by one on the spot and observe its visibility whether it clear, not clearly or not able to see it at all.
Observation-Materials through which you can see clearly are transparent, such as glass piece. Materials through which you cannot see clearly are translucent, such as oil-coated paper. Materials through which you cannot see at all are opaque, such as coal, wood, sugar, wax, coin, and sponge.
So by doing such type of methods we conclude that materials are classified based on their properties.