Question

mention any four physical change and chemical change

Answer 1

Every day in our surrounding, we see different types of physical and chemical changes such as growing of trees, rising and setting of the sun, different shape and size of the moon, burning paper, coal and wood etc. But, have you ever tried to understand the changes? Let us look at this concept in-depth.

It is necessary to understand the terms that are physical properties, chemical properties, reversible and irreversible before knowing the scientific reason for changes. These do not happen just randomly! There are many things responsible for these physical and chemical changes.

Physical and Chemical Changes

Physical Properties: It is known as shape, size, and state of the substance. For example, if you take a sheet of paper and fold it then its shape changes. This change of shape is the physical properties. Examples include tearing of paper sheet, melting of wax, melting of ice into water, Frizzing of water, vaporization process where the change of water into vapour, condensation process where the change of vapour into the water, Stretching of a rubber band.

Chemical Properties: It is the internal properties of a substance. For example, we can get curd from milk because it is the product of milk but for each of them, internal properties are completely different. Examples are: Burning of paper, fuel, wood or anything.

Reversible: Some things and processes are there which we can be reversed this is known as reversible. For example, if you take a folded sheet of paper this folded sheet of paper also we can be unfolded. So folding a sheet of paper is a reversible process. Similarly, we can get back hydrogen and oxygen from water.

Irreversible: Some things and processes are there which we cannot be reverse this is known as irreversible. For example, when we made curd from milk then again from that curd we cannot form milk. So this is an irreversible process.

Characteristics of Physical Changes

In this only, the physical properties of a substance will change nothing else.

In this change, no new substance is formed.

Most of the physical changes that we know are reversible in nature.

Characteristics of Chemical Changes

For a substance, only the chemical properties will change.

Here new substance will form.

Not all but some of the chemical changes are irreversible.

By simple physical means, chemical changes cannot be reversed.

Solved Examples for You

Question: List down the main differences between physical and chemical changes?

Answer:

Physical ChangeChemical Change1. We cannot find any new substance in a physical change.1. Here we can find new substance.2.  It is a temporary change.2.But it is a permanent change3. This change is reversible.3.This change is irreversible.4. In a physical change, very little heat or light energy is usually absorbed or given out.4. In a chemical change, a lot of heat or energy is absorbed or given out.5. In a physical change, the mass of a substance does not alter.5. But in a chemical change, the mass of a substance alter.

Answer 2

Hope it will help you