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Chemical Properties. BY: BRIANNA SHIELDS. DO NOW. On the last page of your note packet from last class: Label the arrows on the diagram with the words evaporation, melting, freezing and condensation Also, label where the solids, liquids and gases exist Work with your group members. GOAL.
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Chemical Properties BY: BRIANNA SHIELDS
DO NOW • On the last page of your note packet from last class: Label the arrows on the diagram with the words evaporation, melting, freezing and condensation • Also, label where the solids, liquids and gases exist • Work with your group members
GOAL • To distinguish between physical and chemical changes
Chemical Changes Changing the substance into a new one by changing atoms
Other Chemical Indicators 1. Burning 2. Foaming/Fizzing/ Bubbling
Other Chemical Indicators 3. Odor change 4. Color change 5. Corroding Acids
Other Chemical Indicators 6. Rusting metal (iron + oxygen = rust) 7. Explosions (fireworks) 8. Verdigris- greened statutes (copper + sulfur)
Other Chemical Indicators 9. Cooking & some food production (cake baking, cheese production) 10. Chemical processes in nature (photosynthesis)
Chemical Change A substance changes into a new and different substance The atoms are altered Often involves chemical rx Physical and Chemical Changes
Foaming (gas formation) Ex: antacid in water
Corrosion due to acids (bubbling or fizzing)
ACIDS Corrosive Sour taste pH paper 1-6 (reddish) Turns litmus red Phenopthalein in acid (no color change) Vinegar & lemon juice BASES Corrosive, slippery Bitter taste pH paper 8-14 (bluish) Turns litmus blue Phenopthalein in base turns pink Soaps, cleaning products 2 chemical indicators
Acids & Bases • Watch the demonstrations at the front counter- are the substances acids or bases? How do you know?
Physical or Chemical Change? • Painting a statue • Chopping wood • Crushing sugar crystals • Dissolving salt • Boiling water • Exploding firecrackers • Mixing baking soda & vinegar
Physical or Chemical Change? • Rotting eggs • Crumpling wax paper • Slicing cucumber • Fizzing antacid in water • Lighting a match • Zipping a coat up • Rusting bike chains