Physical Properties

Everything we see around us is composed of matter, and it can be described as anything that has mass and occupies space. It exists in four states–solid, liquid, gas, and plasma. All substances possess unique properties by which they can be recognised. Matter possesses two types of properties, physical properties and chemical properties. Physical properties of matter can be observed without changing the sample of matter into a completely new substance. Simply put, we can perceive these properties with the help of our senses. Some examples of physical properties are colour, melting point, boiling point, length, shape, etc.

Types of Physical Properties

Physical properties are further divided into two categories:

Intensive properties

Intensive properties will not change irrespective of the amount of matter present in the sample–they remain the same regardless of size, shape, or scale. For example, water has a boiling point of 100°C, which will remain the same no matter the amount of sample.

Extensive properties

Extensive properties will change with changes in the amount or size of the sample. For instance, an ice cube will occupy more space when melted into water.

Examples of Physical Properties

Examples of physical properties are:

Colour

Colour is the hue of a substance perceived by the sense of sight. For example, aluminium is grey in colour.

Boiling point

The highest temperature at which a liquid turns into gas. Water boils at 100°C.

Melting point

The temperature at which a solid substance turns into liquid. Aluminium melts at 660°C.

Density

Density is the amount of mass present in a unit of substance. Water has a density of 1g/ml.

Length

Length is the longest dimension of a body.

Volume

Volume is the space that an object occupies. Some examples are cylinder, cube, pyramid.

Mass

Mass is the amount of matter present in a substance. It stays the same all over the universe.

Weight

It describes how heavy an object is. An object’s weight is directly proportional to the gravitational pull. Weight can change with a change in gravity.

Lustre

Metals are lustrous.

Hardness

Hardness is defined as how hard a substance is. A diamond is said to be the hardest known substance.

Physical Changes

Physical change is a change that a substance undergoes in its physical properties. Physical changes are generally reversible. For instance, a cube of ice melts when heated but, after freezing, turns back to ice. The same substance present before is present after undergoing physical change. There is no energy generated.

Some examples of physical changes are melting an ice cube, chopping wood, mixing water and oil, crushing a can, cutting a piece of paper, melting wax, etc.

Chemical Changes

Chemical changes are those in which one or more new substances are formed. Examples of chemical changes include the ripening of fruits, rusting of iron, digestion of food, etc. These changes are irreversible in nature as they change the chemical properties of a substance. When a substance undergoes a physical change, it produces one or more types of matter different from the original substance. Energy such as heat, light, or sound is generated. Examples of chemical changes are burning wood, baking a cake, boiling an egg, etc.

Conclusion

All substances have a unique set of physical and chemical properties through which they can be identified and undergo physical and chemical changes. Physical properties can be measured without changing the composition of the test sample. Physical properties are of two types, intensive and extensive. Some physical properties are boiling point, melting point, hardness of the substance, etc. Chemical properties describe how a substance will react to different substances. Examples of chemical properties are acidity, flammability, etc.