What is the Difference Between Physical and Chemical Change?
In chemistry, concepts or topics are either derived through chemical and physical reactions or the changes caused by them directly or influential. So, students must understand these changes to learn further topics in the subject. Thus, to help you, we have put together a detailed guide about the ‘Difference Between Physical Changes and Chemical Changes’, Characteristics, as well as examples for a better understanding.
What is a Physical Change?
A Physical Change is defined as a reversible change where the physical properties of the component or matter change. These properties include the change in shape and size of the component. However, when a physical change is observed in a material, there will not be any chemical change in the properties of the said component. For example, water can be turned into liquid and solid form, but the chemical properties such as melting and boiling point do not change.
In physical change, there are alterations in form and appearance, but not in molecular composition. These are mostly changes that are not stable, and it is often easier to revert to original forms, this being one of the key physical change characteristics.
What is a Chemical Change?
As you can understand from the title, when a chemical substance is transformed by another then it is referred to as a chemical change. Besides, the main difference between chemical and physical change is that it is not reversible, thus the properties of the chemical substance also change with the reaction. For example, materials such as paper and wood, when burned turn into ash.
If we were to explain the definition and chemical change characteristics as per the subject, it is a reaction a process or a development, where atoms of substances are altered in their order or position, to form a new substance. In case of chemical change of any substance, the chemical character or composition is modified, and a new and different configuration manifests. In a chemical change, these substances that participate in the alteration are referred to as reactants, while the outcome of the reaction is termed a product. One of the key chemical change characteristics is that it cannot be reversed.
Difference Between Physical and Chemical Change
Now that you have a good idea about Physical and Chemical changes, let us now discuss the differences between Physical and Chemical Changes.
| Parameter | Physical Change | Chemical Change |
| Definition | The change in the molecules is forced to rearrange themselves, not affecting the physical attributes of the component. | A chemical change is a complete transformation of a substance from one form to another, and thus chemical composition also changes. |
| Nature | Physical Change is reversible. | While Chemical change is irreversible. |
| Energy | It does not cause either evolution or absorption of energy. | In a chemical change, both energy evolution and absorption are observed. |
| Substance | Because of the Physical change, no new substance is formed. | Whereas in Chemical change, one or more new substances can be observed. |
| Type of Change | This type of change is considered to be temporary. | However, a chemical change is said to be a permanent change. |
| Examples | Boiling of Water, Melting of Wax, Freezing of water, etc. | Rusting of Metal, Burning of Coal, Digestion of Food, etc. |
Characteristics of Physical and Chemical Change
Both Physical and Chemical changes have unique characteristics as listed in brief today.
Physical Change Characteristics
- When a physical change is observed, the energy is not released in any form
- However, in a physical change, only the physical properties of the material change, thus no new substance is formed. In case of any physical change, the sample of matter undergoes change but the character of the substance does not change, thus retaining the distinct nature of the matter. This can be explained as follows: water is boiled to transform into water vapour. Despite the change in the physical form, the molecules remain the same. Each water molecule continues to be composed of two hydrogen and one oxygen molecule.
- As stated above, Physical change is also reversible. An ice cube that is frozen in state can be melted to become water and can be frozen again to become ice.
- Physical change usually involves a change in the shape, colour, and size of the object
- In a physical change, little or no energy is absorbed or let out.
- Lastly, there is no chemical change observed in the object, and thus chemical properties remain the same
- Certain forces trigger and determine physical change. These can be movement, temperature, and pressure.
Chemical Change Characteristics
- In a chemical change, due to the chemical reaction observed, energy is either released or absorbed
- Also, once a chemical change occurs in an object, it cannot be reversed
- When a chemical change occurs, a precipitate is formed, as two or more new substances are created
- Furthermore, when a chemical change occurs in a substance, its volume also changes, due to the absorption or release of energy
- In chemical change, massive amounts of energy are absorbed or released, in the form of heat, sound, or light
- Besides, chemical change also causes changes in colour, change in its state, and temperature
Factors that signal chemical changes
- There is a change in the temperature, which can be a rise or fall
- Light can be given off
- Colour, smell, and taste can change
- Gas creation
- Bubbles formation
- Solid method manifestation
Examples of physical change
Some of the most common examples of physical change are condensation, melting, boiling, vaporization, and FP/MP/BP of water.
- A glass breaks
- An ice melts
- A paper is a shred
- Silver is cast in a mould
- A sheet of paper is crumpled
- Water boiling
- Brewing of liquids
- Carbon transforming into diamond from graphite
Examples of chemical change
Some examples of chemical change include metabolism, combustion, corrosion, rusting, decay, certain kinds of cooking, etc.
- Cake is baked
- Iron rust
- Yogurt that turns sour
- Milk that turns curd
- Food that breaks into energy
- Caramelization of sugar
- Acid and base combination
Conclusion
In the article above, we have provided a comprehensive description of the physical change vs chemical change along with examples in great detail. Besides, if you have further doubts about any other topics or chapters. Then it is suggested to join the Online Interactive Classes offered by our Tutoroot platform, where you can get various benefits such as Exclusive Doubt Clarification Sessions, Expert Staff Guidance, Access to Best Education Materials, and many more.
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Frequently Asked Questions
How is chemical change different from physical change?
In a physical change, only the appearance of the component is transforming, while in a chemical change complete substance will get altered.
Is original matter lost in chemical change?
Yes, the original matter will be lost during the chemical change, thus affecting the physical as well as chemical properties of the matter.
How is a chemical change different from a physical change?
A physical change is defined as a reversible change where the physical properties of the component or matter change. These properties include the change in shape and size of the component. However, when a physical change is observed in a material, there will not be any chemical change in the properties of the said component. In physical change, there are alterations in form and appearance, but not in molecular composition. These are mostly changes that are not stable, and it is often easier to revert to original forms, this being one of the key physical change characteristics.
When a chemical substance is transformed by another then it is referred to as a chemical change. Besides, the main difference between chemical and physical change is that it is not reversible, thus the properties of the chemical substance also change with the reaction. It is a reaction a process or a development, where atoms of substances are altered in their order or position, to form a new substance. In case of chemical change of any substance, the chemical character or composition is modified, and a new and different configuration manifests.