I think the correct answer from the choices listed above is option B. The reactants calcium sulfide and sodium sulfate will react and form a precipitate which is calcium sulfate since it is only slightly soluble in aqueous solution. Hope this answers the question.
Crust, the upper layer of the Earth, is not always the same. Crust under the oceans is only about 5 km thick while continental crust can be up to 65 km thick. Also, ocean crust is made of denser minerals than continental crust.
The tectonic plates are made up of Earth’s crust and the upper part of the mantle layer underneath. Together the crust and upper mantle are called the lithosphere and they extend about 80 km deep. The lithosphere is broken into giant plates that fit around the globe like puzzle pieces. These puzzle pieces move a little bit each year as they slide on top of a somewhat fluid part of the mantle called the asthenosphere. All this moving rock can cause earthquakes.
The asthenosphere is ductile and can be pushed and deformed like silly putty in response to the warmth of the Earth. These rocks actually flow, moving in response to the stresses placed upon them by the churning motions of the deep interior of the Earth. The flowing asthenosphere carries the lithosphere of the Earth, including the continents, on its back.
It would most likely be .org or .com :)
Your welcome :D