7SCI-Q2-T7-The Theory of Plate Tectonics

A map sequence shows continents as a single landmass about 250 million years ago, then partly separated 115–200 million years ago, and finally today. Which reasoning best explains the changing arrangement of continents over time?

• Earth’s rotation flings continents toward the equator

• Ocean tides push continents westward each day

• Wind erosion shifts continents across the oceans

• Mantle convection slowly moves lithospheric plates

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NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

Scientists use satellites to measure plate motion at 1–10 centimeters per year. Over millions of years, what conclusion can you draw about the impact of these rates?

• Small yearly motion accumulates into major continental shifts

• Rates are too tiny to change coastlines significantly

• Movements cancel out, keeping continents stationary

• Short bursts of speed make continents jump suddenly

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NGSS.HS-ESS1-5

The lithosphere is broken into puzzle-like plates that move relative to each other. Which inference best predicts where earthquakes and volcanoes are most likely?

• Only near the North and South Poles

• Randomly scattered across all oceans

• Along boundaries where plates interact

• In the centers of stable plates

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NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

The term theory in science is used for ideas supported by diverse evidence. If new satellite data matches fossil and rock evidence for continental drift, what should scientists do?

• Strengthen the theory by integrating the new evidence

• Rename the idea as a guess or speculation

• Ignore data that conflicts with old maps

• Discard the theory and start from scratch

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NGSS.HS-ESS1-5

Convection involves material rising when it becomes less dense and sinking when it becomes denser. Using the boiling water analogy, what chain of events in the mantle drives plate motion?

• Heating reduces density, rock rises; cooling increases density, rock sinks

• Density stays constant, rock neither rises nor sinks

• Cooling reduces density, rock rises; heating increases density, rock sinks

• Heating increases density, rock sinks; cooling reduces density, rock rises

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NGSS.HS-ESS2-3

The mantle is heated from below by Earth’s core and radioactivity. How does this energy source shape plate boundaries over time?

• Rising warm mantle creates spreading centers; sinking cool mantle drives subduction

• Warmth makes plates expand evenly; continents stop drifting

• Heat pushes plates outward uniformly; boundaries weaken everywhere

• Energy melts the entire lithosphere; boundaries vanish

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

A diagram labels cooler, denser rock sinking toward the core and warmer, less dense rock rising. Which prediction about surface features follows from this circulation?

• Mid-ocean ridges form where upwelling mantle spreads plates

• Deep-sea trenches form only at ridge crests

• Mountains grow only in plate interiors

• Ridges appear where cold rock sinks downward

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NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

NGSS.HS-ESS2-3

Continental plates once collided to form Pangaea between 350 and 250 million years ago. Which reasoning best explains how scientists reconstructed this event?

• Matching coastlines, fossils, and measured plate motions

• Eyewitness reports from ancient civilizations

• Uniform ocean currents aligning continents

• Random chance aligning maps without evidence

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NGSS.HS-ESS1-5

NGSS.HS-ESS1-6

A map shows the North American, Eurasian, African, South American, and Antarctic plates with arrows indicating motion. Using this context, which statement best explains why continents change position over millions of years?

• Oceans pull continents inward toward trenches

• Plates drift as mantle flow pushes them slowly

• Winds move continents across the ocean surface

• Continents expand as rocks grow outward quickly

Tags

NGSS.HS-ESS1-5

NGSS.HS-ESS2-1

The key on a global plate map uses three boundary symbols and arrows. If red arrows on either side of a boundary point away from each other, which boundary type is indicated?

• Transform boundary where plates slide

• Convergent boundary where plates collide

• Inactive boundary where plates stop

• Divergent boundary where plates separate

Tags

NGSS.MS-ESS2-3