Question 1
The dissolved materials in seawater are thought to originate from chemical weathering of rocks on the continents and also from ________.
◦ outgassing of elements from Earth's interior
◦ meteorites
◦ evaporation of fresh water
◦ erosion
◦ organisms
Question 2
Scientists infer that chemical weathering of crustal rocks is not the only source of some minerals, such as chlorine, bromine, sulfur, and boron because ________.
◦ those minerals have the wrong isotopic composition for weathering products of crustal rocks
◦ some of the minerals are only found in meteorites and must have an extraterrestrial source
◦ the minerals are highly reactive and are not found as compounds that would come from crustal material
◦ there are more of those minerals in the oceans than can be derived from crustal rocks alone
◦ none of the above
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