Meredith wants to use a model to study how interesting formations such as arches, towers, and balanced rocks are made by erosion. she learns in science class that these can form when different layers of the rock erode at different rates. meredith decides to use running water to cause the erosion. to model the rock, she can choose from the following: potting soil clay pebbles plaster sand how should meredith make her model of the rock? a. by using each material to make a separate model b. by arranging the possible materials in strips, one next to the other c. by mixing all the materials together evenly d. by arranging the possible materials in layers, one on top of the other reset submit

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)