Basic Definitions| Matter, Substance, Element, Compound. Mixture, Homogeneous mixture and Heterogeneous mixture Examples (for Grade - 9 students)

Basic Definitions| Matter, Substance, Element, Compound. Mixture, Homogeneous mixture and Heterogeneous mixture Examples (for Grade - 9 students)

Question: Define following terms: 

Matter

Substance

Element

Compound

Mixture

Homogeneous mixture

Heterogeneous mixture

Answer

Matter: 

Matter can be anything that occupies space (volume) and has mass. Example, book, table, walls, chairs, plants, animal, etc. 

Substance: 

Substance is a matter that has a particular set of characteristics that differ from the characteristics of another kind of matter. For example, oxygen, water, carbon monoxide, carbon dioxide, urea, glucose, common salt etc are different substances. 

Element: 

A substance that cannot be converted to other simpler substances is known as an element. or A substance which has all atoms of same atomic number is called element. For example substances like oxygen, hydrogen, iron, copper, aluminum etc. are elements. 

Compound: 

A compound is a pure substance that consists of two or more elements held together in fixed proportions by natural forces (chemical bonds). The properties of compounds are different from the properties of the elements from which they are formed. For example, water, carbon dioxide, copper sulphate, sodium chloride etc., are compounds. Elements and compounds have uniform composition throughout. 

Mixture: 

An impure substance that contains two or more pure substances that maintain their individual chemical characteristics is called a mixture. A mixture can be converted into two or more pure substances by a physical method. Examples of mixture are air, water containing dissolved oxygen, table salt dissolved in water, salt + sand etc. 

Heterogeneous mixture: 

A mixture that is not uniform and consists of two or more visibly different components is called a heterogeneous mixture. For example sand + salt, oil floating on water, mixture of immiscible liquids etc. 

Homogeneous mixture: 

A mixture that is uniform and consists of only one phase is called a homogeneous mixture. For example, sugar mixed in water, salt dissolved in water, mixture of miscible liquids. Homogeneous mixtures also have uniform composition throughout.

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