Lesson 4 Understanding weather

. What is the primary layer of the atmosphere where weather occurs?

• Stratosphere

• Troposphere

• . Mesosphere

2. Which three elements are essential for weather formation?

• A. Gravity, pressure, and wind

• B. Sun, moon, and stars

• C. Air, water, and heat

3. How do scientists who study weather patterns and make forecasts identify themselves professionally? 

• A. Meteorologists

• B. Climatologists

• D. Weather analysts

What happens to air molecules when they are heated?
A. They become more dense

• They become more dense

• They stop moving completely

• They move farther apart

 What is the process called when liquid water changes into water vapor?

• Condensation

• Precipitation

• Evaporation

What type of clouds are thin, white, and have fuzzy edges that look like feathers?

• Cumulus clouds

• Cumulus clouds

• Cirrus clouds

What causes thunder during a storm?

• Cloud collision  

• Lightning heating and expanding air

• Wind turbulence

8. What percentage of Earth is covered by water?

• 50%

• 65%

• 75%

What instrument do meteorologists use to measure air pressure?

• Thermometer

• Barometer

• Anemometer

What determines whether precipitation falls as rain, snow, sleet, or hail?

• Wind speed

• Temperature

• Humidity level