Question

multiple-choice question
what are indicators that a chemical change has happened?
water freezing to ice
painting a room to change the color

the glow from a candle
releasing the gas from a soda can

the smell of a rotten fruit

Explanation:

• Water freezing to ice is a physical change (state change, no new substance).
• Painting a room is a physical change (applying paint, no new substance).
• Candle glow: Candle burning (glow is from combustion) produces new substances (CO₂, H₂O), so it's a chemical change.
• Releasing gas from soda: Physical change (dissolved gas escaping, no new substance formed).
• Rotten fruit smell: Fruit decomposition (chemical change, new substances from decay, smell is from those new substances).

Answer:

• the glow from a candle
• the smell of a rotten fruit