Question

part 3: sorting real - world changes
place each situation in the correct column.
situations to sort:

• ice melting in a cup
• crushing a can
• evaporation of rubbing alcohol
• photosynthesis in a plant
• food spoiling
• combustion of gasoline

physical changes
chemical changes

Explanation:

To determine physical and chemical changes:

• Physical Changes: No new substance is formed, only state/shape changes.
• Ice melting: Solid → liquid (state change, no new substance).
• Crushing a can: Shape change (no new substance).
• Evaporation of rubbing alcohol: Liquid → gas (state change, no new substance).

• Chemical Changes: New substance is formed (involves reactions).
• Photosynthesis: \( \text{CO}_2 + \text{H}_2\text{O}

ightarrow \text{Glucose} + \text{O}_2 \) (new substance).

• Food spoiling: Microbial action creates new compounds (e.g., acids, toxins).
• Combustion of gasoline: \( \text{Gasoline} + \text{O}_2

ightarrow \text{CO}_2 + \text{H}_2\text{O} \) (new substances).

Answer:

Physical Changes:

• Ice melting in a cup
• Crushing a can
• Evaporation of rubbing alcohol

Chemical Changes:

• Photosynthesis in a plant
• Food spoiling
• Combustion of gasoline