Question

6 reflections and conclusions
how can you distinguish between a physical change and a chemical change?
7 choose one of the clue words from the physical - change column and one from the chemical - change column, and give an example of each of those types of changes
8 sometimes early in the morning, the grass is wet and you notice that the car windshield is wet also. you know it didnt rain. how can you explain this as either a physical or chemical change?

Explanation:

1. A physical change alters physical properties like shape, state, without changing the substance's chemical composition. A chemical change results in a new substance with different chemical properties, often with signs like heat, light, gas production.
2. For example, "melting" (physical change) - ice melting into water just changes state from solid to liquid. "Burning" (chemical change) - wood burning produces ash, carbon - dioxide, heat and light, a new substance is formed.
3. The wetness on grass and car windshield in the morning without rain is due to dew formation. This is a physical change. Water vapor in the air cools down and condenses into liquid water droplets on cool surfaces, without changing the chemical nature of water.

Answer:

1. Physical change: no new substance formed, only physical properties change. Chemical change: new substance with different chemical properties formed.
2. Physical change example: melting (ice to water). Chemical change example: burning (wood burning).
3. It is a physical change (dew formation by condensation of water vapor).