Evaporation & Condensation
What process turns liquid water on Earth's surface into water vapor?
Evaporation.
What is precipitation? Give one example.
Precipitation is water falling from the atmosphere to Earth; example: rain.
What are clouds primarily made of?
Tiny liquid water droplets and/or ice crystals.
Name one way humans can conserve freshwater at home.
Examples: fix leaks, take shorter showers, turn off faucet while brushing teeth, use drought-tolerant plants.
Name the process by which water vapor cools and changes back into liquid water droplets.
Condensation.
List three forms precipitation can take.
Rain, snow, sleet, hail (any three).
Define humidity in simple terms.
Humidity is the amount of water vapor in the air.
Give one human activity that can pollute freshwater sources.
Examples: industrial discharge, agricultural runoff (fertilizers/pesticides), improper waste disposal, oil spills.
Explain why warmer air increases the rate of evaporation.
Warmer air gives water molecules more energy so they move faster and escape as vapor more quickly; higher temperature increases evaporation rate.
Explain how runoff contributes to the collection stage of the water cycle.
Runoff is water that flows over the land into streams, rivers, lakes, or oceans, adding to surface collection.
Describe how relative humidity affects how comfortable people feel on a hot day.
High relative humidity makes it feel hotter because sweat evaporates more slowly, reducing cooling; low humidity makes evaporation faster and feels cooler/drier.
Explain how deforestation can affect the local water cycle.
Removing trees reduces transpiration and increases runoff and erosion; fewer roots to hold soil can change infiltration and groundwater recharge, altering local precipitation patterns and water availability.
Describe how condensation forms on the outside of a cold glass of water.
Water vapor in the warm air touches the cold surface of the glass, cools, and changes back into liquid droplets (condensation).
Describe how groundwater is formed and how it is different from surface water.
Groundwater forms when water infiltrates soil and fills underground aquifers; it's stored below ground, whereas surface water is in rivers, lakes, and ponds.
Explain the difference between stratus, cumulus, and cirrus clouds (one sentence each).
Stratus: low, flat layers often bringing overcast skies;
Cumulus: puffy, cotton-like clouds often with flat bases;
Cirrus: thin, wispy high-altitude clouds made of ice crystals.
Describe two ways cities can reduce stormwater runoff and protect water quality.
Green roofs, permeable pavements, rain gardens, retention ponds, and increased tree canopy can slow runoff, increase infiltration, and filter pollutants.
Give the term for the process where water moves from plant leaves into the atmosphere and explain how it connects to evaporation and condensation.
Transpiration — water is released from plant leaves as vapor; together with evaporation these make evapotranspiration which supplies moisture to the atmosphere and later condenses.
Explain how a watershed works and why it is important for water collection and local ecosystems.
A watershed is an area of land where all water drains to a common outlet (stream, lake, or ocean); it collects precipitation and channels it—important because land use affects water quality and quantity in that watershed.
Describe how cloud formation relates to air pressure and temperature changes in the atmosphere.
Rising warm air cools, reducing its capacity to hold water vapor; as temperature drops or pressure changes, vapor condenses into cloud droplets—low pressure and rising air favor cloud formation.
Propose a short school or community project (2–3 sentences) that would help protect or conserve local water resources; include one measurable goal.
Example project: Start a rain garden at school to capture runoff from the parking lot with a goal to divert and filter at least 10,000 liters of stormwater each school year; track water captured and number of native plants installed.