Explain how radioactive decay has always warmed the earth from the inside, and nuclear fusion has always warmed the earth from the outside
A) Much heat was released as matter coalesced to form the earth. This heat resulted in the production of radioactive isotopes, which still reside within the earth today and are a source of internal heat. Our primary external source of heat is from the fusion of hydrogen within the sun.
B) The inner Earth is made of fissioning heavy elements while the sun is made of lighter fusing elements.
C) Radioactive elements have been within Earth since it was created while the sun is made of fusing hydrogen atoms.
D) All of the above are reasonable answers.
C
You might also like to view...
If you observe an angular unconformity, you would infer that the region had experienced ______.
A) deposition in shallow water, uplift or lowering of sea level enough to expose the rocks to erosion and non-deposition for a period of time, and subsequent submergence of the remaining sedimentary units where they experience new deposition B) uplift and tilting of sedimentary units that exposes them to erosion over a period of time with subsequent renewed deposition C) intrusion of igneous rocks into a depositional setting, forcing the sedimentary layers upward and possibly deforming them, followed by subsidence of the remaining sedimentary layers and renewed deposition D) deposition of sedimentary layers on crystalline igneous or metamorphic rocks that are exposed at the surface of the earth
Much of the increasing global need for electricity can be met by solar sources because
A) about 70% of electrical demand occurs when the sun is shining. B) modern battery technology now makes electrical storage cheap and efficient. C) only about one square meter of photovoltaic cells are needed to heat a home. D) even at night most solar power systems run at about 50% of normal capacity.
The best ecosystem management requires
A) good stewardship and sustainability. B) planned disturbances and careful timing. C) restoration ecologists. D) government regulation and control.
The expansion of desert-like landscapes, generally as a result of human activities in marginal lands, is called _______________
Fill in the blank(s) with correct word