CAST — California Science Test Earth as a Planet — practice questions
24 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CAST — California Science Test Earth as a Planet in the app →Scientists work out the layered structure of Earth's interior mainly by measuring what?The charged particles trapped in Earth's magnetosphere flow out from where?Any rock that has cooled from a molten state is placed in which class?What supplies the power that keeps Earth's crustal plates moving?Almost all of Earth's weather takes place in which layer of the atmosphere?Which gas makes up the largest share of the air at Earth's surface?Free oxygen first built up in Earth's air as a waste product of which process?What happened over the Tunguska River in Siberia on 30 June 1908?New oceanic crust is created at rift zones. Where is the old crust destroyed?Oceanic crust runs about 6 kilometers thick. How thick is continental crust?The San Andreas Fault marks the boundary between which two plates?Who assembled the case for drifting continents in 1920, without a mechanism to explain it?Ozone sits near the top of the stratosphere and shields the surface from what?Effects of the atmosphere that last through decades and centuries are given which name?The great ice ages were primarily the result of changes in what?Carbon dioxide warms Earth's surface because it absorbs which kind of radiation?Earth was struck as often as the Moon, yet shows far fewer craters. What removed them?A worldwide sediment layer from 65 million years ago is rich in which rare metal?Earth's bulk density is about 5.5 grams per cubic centimeter while its surface rocks are near 3. What does thaAbout 2 square kilometers of new ocean floor form every year. What does that rate imply?The Pacific plate slides past the North American plate at about 5 centimeters a year, and the last southern CaCarbonate rocks would release about 70 bars of carbon dioxide if heated, against a present carbon dioxide presThe greenhouse effect currently lifts Earth's surface temperature by about 23 degrees Celsius. What would our The Tunguska body carried the punch of a 5-megaton bomb, yet dug no crater. What explains that?