Important Questions Test: Sorting Materials into Groups

Those substances that have less density than water floats on water surface such as plastic ball and feather.

All metals are good conductor of heat and electricity.

Diamond is the hardest known natural substance due to arrangement of molecule of it.

Sugar is soluble in water while mustard oil, sand and plastic is insoluble in water.

Chair, table and plough are made up of wood obtained from plants.

Those substances that burn easily are called combustible substance. Ghee is animal fat, which is combustible in nature.

Those substances that are attracted by magnet are called magnetic material. Iron is a magnetic material.

Petrol is lighter than water as it floats on water surface when mixed with water.

The properties of metal due to which metal can be beaten into thin sheet is called as malleability. Gold is most malleable metal.

The object through which light passes easily are called as transparent object. Clean glass, glass and thin sheet of plastic are transparent while muddy water is translucent.

The substance through which light do not pass easily is called as opaque object. Brick, book etc are example of opaque objects.

Iron, silver and gold are elements while common salt is compound of sodium and chlorine.

The action of air, water on metal surface is called as corrosion. Due to corrosion metallic objects lose their lustre

The ability of a solute to get dissolved in a solvent is called as solubility.

Rust is the Result of Corrosion of Metallic Iron. Iron is oxidized to Fe²⁺(aq) at an anodic site on the surface of the iron, which is often an impurity or a lattice defect. Oxygen is reduced to water at a different site on the surface of the iron, which acts as the cathode.

The sorting of objects into groups with each group having its own characteristic properties is called classification of objects. All the objects having similar characteristics properties are placed in one group different groups. And the objects having different properties are placed in different groups.
1. The classification of objects into groups makes it easier to locate them and work with them.
2. If we know the properties of any one member of the group, we can get an idea of the properties of the other members of this group.

Newspaper, a book, a copy, a diary are made up of paper obtained from plants.

CNG stands from compressed natural gas which is stored at very high pressure.

The substances that can burn easily are called as combustible substance such as coal , petrol, wood etc.

Non-metals are generally bad conductor of electricity but graphite is good conductor of electricity.