Write answers to the following questions.
(a) How are properties of substances determined?
(b) Explain the differences between compounds and mixtures.
(c) Why is an alloy a mixture?
(d) Why are substances classified?
(a) Properties of substances are determined by the atom present in that substance.
(b) Difference between compounds and mixtures:
Compounds |
Mixtures |
The constituents of compounds are present in a fixed ratio. |
The constituents of mixtures can be present in any ratio. |
Compounds are homogeneous in nature. |
Mixtures may not be homogeneous in nature. |
Properties of compounds differ from the constituent's properties. |
Properties of the mixture resemble the properties of the constituents. |
Constituents of compounds can be separated by chemical methods such as decomposition etc. |
Constituents of mixtures can be separated by physical methods such as evaporation, filtration, distillation etc. |
(c) When a metal is mixed with another element that may be a metal or a non−metal, a new substance of homogeneous composition is obtained. This substance is known as an alloy. Thus, an alloy is a homogeneous mixture of two or more metals, or a metal and a non−metal. For example, steel is an alloy of iron and carbon.
(d) The substances are classified to categorize them according to their properties. Also, the classification of the substances makes the study of their properties simpler.