Physical Change
By: Maria Fontana and Gianna Tufano
What is a Physical Change?
A physical change is changing from one state of matter (solid, liquid or gas) to another state of matter without changing the chemical composition. During a physical change, a material keeps its identity. Physical changes are reversible; whereas, chemical changes are not.
Physical Change vs. Chemical Change Video
The video below explains the difference between physical changes and chemical changes. We chose this video because it is an educational video that would help our classmates get a better understanding of physical changes.
Physical Change Example of Water into Ice
An example of a physical change is freezing water. This is a physical change because the water is changing its state of matter from a liquid to a solid. However, there is no change to the chemical composition because the chemical composition of water and ice are both H20. We can reverse this physical change by melting the ice. Then, the ice will become a liquid again.
Liquid Water
This picture is water in liquid form. It is made up of 2 hydrogen molecules and 1 oxygen molecule which is H20.
Solid Water
When water reaches its freezing point, it becomes ice. This is still H20, so it is a physical change. The water changed states of matter. It went from a liquid to a solid.
Reversing the Physical Change
We can add heat to the ice until it reaches its melting point. Then, the ice will melt into a liquid. The water is now back to its original state of matter.
How Can You Cause a Physical Change?
You can cause a physical change by changing the appearance of the substance without changing the chemical makeup. An example of causing a physical change is cutting wood.
Another example of causing a physical change is cutting a piece of paper in half. Lastly, another example is adding sugar to coffee. The sugar dissolves into the coffee liquid.
Cutting wood
This picture shows an example of cutting wood, which is a physical change. This is an example of a physical change because it is a change in shape of the material.
Cutting paper
This picture shows an example of cutting paper, which is a physical change. This is an example of a physical change because it is a change in size of the material.
Sugar Added to Coffee
This picture shows the sugar dissolving into the coffee. Solubility is the ability of one material to dissolve in another. It is an example of a physical change.