When you study matter in Year 9 Chemistry, it’s important to know the difference between physical changes and chemical changes. Both are key to understanding how substances work and change, but they have different features.
Physical changes are changes that do not change what a substance is made of. Here are some important points:
Reversible: Many physical changes can be undone. For example, when you freeze water to make ice, you can melt it back into liquid water again.
Same Substance: In a physical change, the substance stays the same at the tiny, molecular level. For instance, when salt dissolves in water, it still remains salt and water.
Examples:
On the other hand, chemical changes involve a change that alters what the original substance is. Here’s what you need to know:
New Substances Created: In a chemical change, the original substances change their structure and form one or more new substances. For instance, when iron gets rusty, it combines with oxygen to create rust.
Not Reversible: Many chemical changes are hard or impossible to undo. Burning wood produces ash and smoke, and you can’t turn those back into wood.
Examples:
In summary, physical changes just change how things look or their state without changing what they are made of. Chemical changes create new substances and usually can't be reversed easily. Understanding these differences will help you learn more about materials and how they interact in different chemical reactions. You can see these changes in everyday life—like enjoying a glass of iced tea or watching a fire!
When you study matter in Year 9 Chemistry, it’s important to know the difference between physical changes and chemical changes. Both are key to understanding how substances work and change, but they have different features.
Physical changes are changes that do not change what a substance is made of. Here are some important points:
Reversible: Many physical changes can be undone. For example, when you freeze water to make ice, you can melt it back into liquid water again.
Same Substance: In a physical change, the substance stays the same at the tiny, molecular level. For instance, when salt dissolves in water, it still remains salt and water.
Examples:
On the other hand, chemical changes involve a change that alters what the original substance is. Here’s what you need to know:
New Substances Created: In a chemical change, the original substances change their structure and form one or more new substances. For instance, when iron gets rusty, it combines with oxygen to create rust.
Not Reversible: Many chemical changes are hard or impossible to undo. Burning wood produces ash and smoke, and you can’t turn those back into wood.
Examples:
In summary, physical changes just change how things look or their state without changing what they are made of. Chemical changes create new substances and usually can't be reversed easily. Understanding these differences will help you learn more about materials and how they interact in different chemical reactions. You can see these changes in everyday life—like enjoying a glass of iced tea or watching a fire!