Question

1. matter can undergo physical or chemical changes. which of these are examples of physical changes?

options: silver tarnishing, freezing a popsicle, spoiled milk, breaking an egg, burning paper

Explanation:

To determine physical changes, we check if the substance's chemical identity remains the same (only form/state changes).

• Freezing a popsicle: Liquid to solid (water to ice), no new substance. Physical change.
• Breaking an egg: Changes shape/size, no new substance. Physical change.
• Silver tarnishing: Silver reacts with sulfur (new substance, Ag₂S). Chemical change.
• Spoiled milk: Bacteria cause chemical reactions (new substances). Chemical change.
• Burning paper: Combustion (new substances like CO₂). Chemical change.

So the physical change examples are freezing a popsicle and breaking an egg.

Answer:

Freezing a popsicle, Breaking an egg