Question

During summer holidays, a group of children collected a lump of salt, green grass, broken glass piece, a small thermocol box, pen, iron nail, glass marbles, hair, naphthalene ball, a piece of sugar candy (mishri) and tried to group them on the basis of properties given in Table 4.1 below. Help them in filling the Table.

Name of theMaterial

Appearance(Hard/soft)

Transparency(Transparent/Translucent/Opaque)

Floats/SinksIn water

Soluble/Insoluble in water

Answer 1

Hint: We can say hard materials are those materials that could not be compressed, scratched, bent (or) cut. Some of the examples of hard materials are glass and iron. Soft materials are those materials which could be easily bent, cut, compressed (or) compressed. Some of the examples of soft materials are cotton, sponge etc. We can predict the transparency based on the amount of light passed through them. We can predict the floating/sinking nature based on the density of the object.

Complete answer:
We can say hard materials are those materials that could not be compressed, scratched, bent (or) cut.
Soft materials are those materials which could be easily bent, cut, compressed (or) compressed.
We can say a material is transparent when it allows maximum light to pass through them. We can say a material is translucent when it permits some amount of light to pass through them.
We can say an object is opaque when no light could pass through them.
The substance that is less dense than water floats on the upper layer.
The substance that is denser than water would sink to the bottom and water would float on the upper surface.

Name of theMaterial	Appearance(Hard/soft)	Transparency(Transparent/Translucent/Opaque)	Floats/SinksIn water	Soluble/Insoluble in water
Lump of salt	Hard	Opaque	Sinks	Soluble
Pen	Hard	Opaque	Sinks	Insoluble
Piece of sugarCandy	Hard	Translucent	Sinks	Insoluble
Small thermocol box	Soft	Opaque	Floats	Insoluble
Hair	Soft	Opaque	Floats	Insoluble
Marbles	Hard	Transparent	Sinks	Insoluble
Naphthalene balls	Hard	Opaque	Sinks	Insoluble
Iron nail	Hard	Opaque	Sinks	Insoluble
Glass piece	Hard	Transparent	Sinks	Insoluble
Broken glass piece	Hard	Transparent	Sinks	Insoluble
Green grass	Soft	Opaque	Floats	Insoluble

Note:
Some of the soft materials that we use in the daily basis of our life are leaf, rubber band, eraser, cooked rice, and fresh chapati. Generally, cotton balls float in water at initial stages and when it absorbs water, it sinks. Some of the materials that are soluble in water are honey in water, groundnut oil in mustard oil, glucose in water. Some of the materials that are insoluble in water are mustard oil in water, rice flour in water, and turmeric in water.