What are two examples of physical change?
Physical changes refer to alterations in the form, appearance, or structure of a substance without changing its chemical composition. These changes are usually reversible, meaning the substance can return to its original state. In this article, we will discuss two examples of physical changes: melting and boiling.
Melting is a physical change that occurs when a solid substance absorbs heat and turns into a liquid. An excellent example of this is the melting of ice. When ice is heated, it absorbs energy, causing its molecules to move faster and break the bonds holding them together. As a result, the ice transforms into water. The chemical composition of the ice and water remains the same; it’s just the physical state that has changed. When the water cools down, it can freeze back into ice, demonstrating the reversibility of this physical change.
Boiling is another example of a physical change that involves the conversion of a liquid to a gas. This process occurs when a liquid is heated to its boiling point, which is the temperature at which the vapor pressure of the liquid equals the atmospheric pressure. As the liquid absorbs heat, its molecules gain energy and move faster, eventually breaking free from the liquid and turning into gas. An everyday example of boiling is when water is heated in a pot and turns into steam. Similar to melting, the chemical composition of the water and steam remains the same; it’s the physical state that has changed. When the steam cools down, it can condense back into water, showcasing the reversibility of this physical change.
In conclusion, melting and boiling are two examples of physical changes that involve alterations in the form, appearance, or structure of a substance without changing its chemical composition. These changes are usually reversible, making them essential in various processes and phenomena in our daily lives.
