* Physical Change: A physical change alters the form or appearance of a substance but does not change its chemical composition.
* Chemical Change: A chemical change results in the formation of new substances with different chemical properties.
Here's how the lemon affects the tea:
1. Lemon Juice Contains Citric Acid: Lemon juice is acidic due to the presence of citric acid.
2. Citric Acid Reacts with Tannins: Tea contains tannins, which are natural compounds that contribute to its bitterness and astringency. When citric acid from the lemon mixes with tannins in the tea, it causes them to precipitate out of solution.
3. Precipitation: This precipitation forms tiny, suspended particles that scatter light, making the tea appear cloudy.
Key Point: The chemical composition of the tea and lemon juice hasn't changed. The citric acid and tannins have simply interacted to form a new, insoluble compound that's suspended in the tea, giving it a cloudy appearance.
Let me know if you have other questions!
