Gr7 Sci 407 USA FY21 Question: 1-
Crabs are organisms that have five pairs of legs. In certain species of crabs, the fifth pair of legs has a flattened, paddle-like shape
evolved?
Crabs were exposed to a toxin in the water.
c Crabs with this adaptation have an advantage over other crabs to defend against predators in oyster beds.
Crabs needed this adaptation to dig into sand to find food so they developed the flattened paddle-like shape.
O Crabs developed this adaptation because they needed to climb mangrove trees to hide themselves from predators.
o

Acurium-245 nucleus is hit with a neutron and changes as shown by the equation. complete the equation by filling in the missing parts. 52

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base

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.)