Science Earth and Space Science Flashcards
6 cards from real GED practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Science Earth and Space Science flashcards as text
What is the primary cause of ocean tides on Earth?
Answer: The gravitational pull of the Moon (and Sun)
Tides are primarily caused by the gravitational pull of the Moon on Earth's oceans. The Sun also contributes but to a lesser degree. The Moon's gravity creates bulges of water on the sides of Earth facing toward and away from the Moon.
How do scientists use the half-life of radioactive isotopes to determine the age of rocks and fossils?
Answer: By comparing the ratio of parent to daughter isotopes in a sample
Radioactive isotopes decay at a known constant rate (half-life). By measuring the ratio of remaining parent isotope to daughter product, scientists calculate how long the decay has been occurring.
What process drives the movement of tectonic plates?
Answer: Convection currents in Earth's mantle
Convection currents in the semi-molten mantle drive plate movement. Hot material rises, spreads, cools, and sinks, creating a conveyor-belt-like motion that moves the plates above.
The Hertzsprung-Russell (H-R) diagram classifies stars based on which two properties?
Answer: Temperature and luminosity (brightness)
The H-R diagram plots stars by surface temperature (x-axis, hot on left) versus luminosity/brightness (y-axis). This reveals patterns including the main sequence, giants, supergiants, and white dwarfs.
What happens at a convergent plate boundary where oceanic crust meets continental crust?
Answer: The oceanic crust subducts beneath the continental crust, forming mountains and volcanoes
Oceanic crust is denser than continental crust, so it subducts (sinks) beneath the continental plate. This creates deep ocean trenches, volcanic mountain ranges, and earthquakes.
In which layer of Earth does the material behave like a slow-moving fluid, allowing tectonic plates to move?
Answer: Mantle
The mantle, particularly the asthenosphere layer, is composed of semi-molten rock that behaves plastically (like a very thick fluid) over long timescales, enabling tectonic plate movement.