Changes Around Us

What is the process by which a liquid changes into a gas?

• Sublimation

• Evaporation

• Solidification

• Condensation

Give an example of a reversible change.

• Burning wood into ash and turning the ash back into wood

• Melting ice into water and freezing the water back into ice

• Boiling water into steam and condensing the steam back into water

• Evaporating water into vapor and liquefying the vapor back into water

Explain the concept of evaporation.

• Evaporation is the process of solid turning into a gas.

• Evaporation occurs when a gas turns into a liquid.

• Evaporation is the process by which a liquid turns into a gas due to an increase in temperature.

• Evaporation is caused by a decrease in temperature.

What is condensation and when does it occur?

• Condensation is the process in which a gas or vapor turns into a liquid. It occurs when the temperature of the gas or vapor decreases to the point where the molecules lose enough energy to form a liquid.

• Condensation is the result of a gas turning into a solid.

• Condensation occurs when the temperature of a liquid increases.

• Condensation is the process of turning a solid into a gas.

Describe a physical change that you observe in your daily life.

• Burning of paper into ashes

• Melting of ice into water

• Boiling of water into steam

• Freezing of water into ice

What are some examples of chemical changes?

• Freezing of water, Boiling of water, Cutting paper

• Rusting of iron, burning of wood, cooking an egg, baking a cake

Explain the concept of sublimation.

• Sublimation is the transition of a substance from gas to solid phase.

• Sublimation is the transition of a substance directly from the solid phase to the gas phase without passing through the intermediate liquid phase.

• Sublimation is the process of converting a liquid directly to a gas.

• Sublimation is the change of a gas directly to a solid without passing through the liquid phase.

How does rusting of iron demonstrate a chemical change?

• Rusting of iron is a mechanical change due to the impact of external forces.

• Rusting of iron is a biological change caused by the growth of bacteria.

• Rusting of iron is a physical change because it only involves a change in color.

• Rusting of iron demonstrates a chemical change because it involves the formation of iron oxide through a chemical reaction with oxygen and water.

Discuss the importance of understanding changes in our environment.

• Changes in the environment are irrelevant to human activities

• Ignoring changes in the environment is the best approach

• Understanding changes in the environment has no impact on daily life

• It is important to understand changes in our environment to adapt, mitigate negative impacts, and make informed decisions for sustainable living.

Changes that take place in nature by themselves are called _______