Air Masses, Fronts, Humidity, and Condensation

What is an air mass?

• A small pocket of air over a city

• A large body of air with the same temperature and humidity

• A strong gust of wind

• A type of storm

Answer explanation

An air mass is defined as a large body of air that has uniform temperature and humidity characteristics. This distinguishes it from smaller pockets of air or weather phenomena like storms.

Tags

NGSS.MS-ESS2-5

NGSS.MS-ESS2-6

What is the boundary between two different air masses called?

• A cloud

• A front

• A hurricane

• A tornado

Answer explanation

The boundary between two different air masses is called a front. It is where contrasting air masses meet, leading to various weather phenomena, unlike clouds, hurricanes, or tornadoes, which are different weather-related terms.

Tags

NGSS.MS-ESS2-5

NGSS.MS-ESS2-6

What happens when a warm air mass moves toward a cold air mass?

• The warm air rises over the cold air

• The warm air stays on the ground

• The cold air rises over the warm air

• The warm and cold air mix immediately

Answer explanation

When a warm air mass moves toward a cold air mass, the warm air, being less dense, rises over the cold air. This process is known as convection and is a key factor in weather patterns.

Tags

NGSS.MS-ESS2-5

NGSS.MS-ESS2-6

What happens when a cold air mass moves toward a warm air mass?

• A) The cold air moves under the warm air and pushes it up

• B) The warm air moves under the cold air

• C) The two air masses stay separate

• D) The warm air disappears

Answer explanation

When a cold air mass moves toward a warm air mass, the denser cold air pushes underneath the lighter warm air, causing the warm air to rise. This process is known as lifting, which is why A is the correct answer.

Tags

NGSS.MS-ESS2-5

What kind of weather can happen where two air masses meet?

• Storms and precipitation

• No weather changes

• Only warm, sunny days

• Only strong winds

Answer explanation

When two air masses meet, they can create instability in the atmosphere, leading to storms and precipitation. This is due to the differences in temperature and humidity between the air masses.

Tags

NGSS.MS-ESS2-5

What does 100% relative humidity mean?

• The air is completely dry

• The air is holding the maximum amount of water vapor

• The air is too cold for water vapor

• It is raining

Answer explanation

100% relative humidity means the air is saturated with water vapor, holding the maximum amount it can at that temperature. This is why the correct answer is that the air is holding the maximum amount of water vapor.

Tags

NGSS.MS-ESS2-5

How does the air’s temperature affect how much water vapor it can hold?

• Cold air can hold more water vapor

• Warm air can hold more water vapor

• The temperature does not affect it

• Only frozen air can hold water vapor

Answer explanation

Warm air can hold more water vapor because as temperature increases, the energy of air molecules rises, allowing them to hold more moisture. This is why humid conditions are often associated with warmer temperatures.

What happens when air at 100% relative humidity cools down?

• A) It holds more water vapor

• B) The water vapor turns into liquid

• C) The air becomes warmer

• D) The air dries out

Answer explanation

When air at 100% relative humidity cools down, it can no longer hold all the water vapor, leading to condensation. This process causes the water vapor to turn into liquid, making option B the correct answer.

Tags

NGSS.MS-ESS2-5

What is the process of water vapor turning into tiny droplets called?

• Evaporation

• Condensation

• transpiration

• precipitation

Answer explanation

The process of water vapor turning into tiny droplets is called condensation. This occurs when water vapor cools and changes back into liquid form, forming droplets, which is essential in the water cycle.

Tags

NGSS.MS-ESS2-4

Why do we sometimes see dew on the grass in the morning?

• The air heats up overnight

• The grass releases water

• The air cools and water vapor condenses

• The ground soaks up rainwater overnight

Answer explanation

Dew forms when the air cools overnight, causing water vapor to condense on surfaces like grass. This process is known as condensation, which is why we see dew in the morning.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4