Difference between physical and chemical changes

Question

Hey everyone! 👋 Ever mixed baking soda and vinegar and wondered why it fizzes? Or noticed how ice melts into water? 🤔 These are examples of changes happening all around us, but some changes are *physical* and some are *chemical*. Let's break down the difference in a way that makes sense!

teresajuarez1986 · Accepted Answer

📚 What are Physical and Chemical Changes?Understanding the difference between physical and chemical changes is fundamental to grasping how matter behaves. Let's explore what each entails:

🧱 Defining Physical ChangeA physical change involves altering the form or appearance of a substance, but not its chemical composition. The molecules themselves remain the same, just rearranged.

🧪 Defining Chemical ChangeA chemical change, on the other hand, involves the formation of new substances with different chemical compositions. This involves the breaking and forming of chemical bonds.

🔎 Physical vs. Chemical Changes: A Detailed Comparison

Feature
      Physical Change
      Chemical Change

Definition
      Change in form or appearance without changing the substance's chemical composition.
      Change resulting in the formation of a new substance with a different chemical composition.

Molecular Level
      Molecules are rearranged but remain the same.
      Molecules are broken apart and new molecules are formed.

Composition
      Chemical composition remains the same.
      Chemical composition changes.

Reversibility
      Often easily reversible.
      Usually not easily reversible.

Energy Change
      Energy change is usually small.
      Energy change is often significant (heat or light is absorbed or released).

New Substance Formed?
      No new substance is formed.
      A new substance is formed.

Examples
      Melting ice, boiling water, cutting paper, dissolving sugar in water.
      Burning wood, rusting iron, cooking an egg, baking a cake, reacting vinegar with baking soda.

💡 Key Takeaways

🧊 Physical changes alter the state or form of a substance without changing its chemical identity.
    🔥 Chemical changes result in the formation of new substances with different chemical properties.
    🔄 Many physical changes are reversible, while chemical changes are often irreversible without further chemical reactions.
     🌡️ Energy changes (heat, light) are often more pronounced in chemical changes compared to physical changes.

Difference between physical and chemical changes

1 Answers

📚 What are Physical and Chemical Changes?

🧱 Defining Physical Change

🧪 Defining Chemical Change

🔎 Physical vs. Chemical Changes: A Detailed Comparison

💡 Key Takeaways

Join the discussion

Feature	Physical Change	Chemical Change
Definition	Change in form or appearance without changing the substance's chemical composition.	Change resulting in the formation of a new substance with a different chemical composition.
Molecular Level	Molecules are rearranged but remain the same.	Molecules are broken apart and new molecules are formed.
Composition	Chemical composition remains the same.	Chemical composition changes.
Reversibility	Often easily reversible.	Usually not easily reversible.
Energy Change	Energy change is usually small.	Energy change is often significant (heat or light is absorbed or released).
New Substance Formed?	No new substance is formed.	A new substance is formed.
Examples	Melting ice, boiling water, cutting paper, dissolving sugar in water.	Burning wood, rusting iron, cooking an egg, baking a cake, reacting vinegar with baking soda.