Review for 6th Grade Science Post-Assessment

Wind is mainly caused by...

• gravity moving air around in different directions

• the uneven heating of Earth's surface by the sun

• thunderstorms and tornados that create strong breezes

• the fast movement of cars and planes

Answer explanation

Wind is mainly caused by the uneven heating of Earth's surface by the sun, which creates differences in air pressure. This causes air to move from high to low pressure areas, resulting in wind.

A rising barometer (high pressure) means...

• snow will fall within 24 hours

• storm clouds are probably on their way

• clear skies are likely coming

• unsure; barometers cannot be used to predict future weather

Answer explanation

A rising barometer indicates high pressure, which typically leads to clear skies and stable weather conditions. Therefore, the correct choice is that clear skies are likely coming.

Which of the following does NOT influence a region's climate?

• Elevation

• Nearness to water

• Winds and ocean currents

• Longitude

Answer explanation

Longitude does not directly influence a region's climate, while elevation, nearness to water, and winds/ocean currents do affect temperature and precipitation patterns.

What is the process of hotter, less dense fluids rising and colder, more dense materials sinking?

• Conduction

• Radiation

• Convection

• Circulation

Answer explanation

The process described is convection, where hotter, less dense fluids rise while colder, denser materials sink. This movement creates a cycle that transfers heat, making convection the correct answer.

Which TWO things power (cause) the water cycle?

• gravity

• plate tectonics

• erosion

• solar radiation

• hurricanes

Answer explanation

The water cycle is powered by gravity, which pulls water down, and solar radiation, which heats water, causing evaporation. These two forces drive the continuous movement of water through evaporation, condensation, and precipitation.

Global winds and ocean currents on Earth appear to curve rather than move in straight lines because of...

• The way our eyes perceive movement when viewing a map

• The tilt of the Earth (Law of Superposition)

• Earth's rotation (Coriolis Effect)

• The rapid movement of air and water in different directions

Answer explanation

Global winds and ocean currents curve due to Earth's rotation, a phenomenon known as the Coriolis Effect. This effect causes moving air and water to turn and twist rather than travel in straight lines.

Which image is the MOST accurate scale model of our solar system? (Only consider size and distance).

• 
• 
• 
• 

What do moon phases, seasons, and eclipses have in common?

• They are all caused by the rotation, revolution, and tilt of Earth and the moon.

• They all happen due to natural forces from the sun as it shines on Earth.

• They are all caused by the force of gravity on Earth and the moon.

• They all happen four times a year.

Answer explanation

Moon phases, seasons, and eclipses are all influenced by the rotation and revolution of Earth, as well as the tilt of its axis and the moon's orbit. This interaction determines their occurrence and appearance.

Why is one day on Mercury equal to 58 Earth days?

• Venus has a gravitational pull on Mercury

• Mercury rotates very slowly on its axis

• One revolution of Mercury around the sun takes the same time as one rotation on its axis

• Mercury revolves very slowly around the Sun

Answer explanation

One day on Mercury is 58 Earth days because Mercury rotates very slowly on its axis. This slow rotation means that it takes a long time for Mercury to complete one full spin relative to the Sun.

Earth has seasons because...

• Volcanic eruptions cause different types of weather.

• Earth's axis is tilted as it moves around the sun.

• The distance between the earth and the sun changes throughout the year

• Heat energy from the sun disappears from December to March.

Answer explanation

Earth has seasons because its axis is tilted at an angle as it orbits the sun. This tilt causes different parts of the Earth to receive varying amounts of sunlight throughout the year, leading to seasonal changes.