The power goes out and the only light source you have available is a chemical glow stick. As you sit in the dark with this tiny light source you think
about your lesson on endothermic and exothermic reactions. Do you think
this reaction would be classified as an endothermic or an exothermic reaction?
Be sure to state your evidence and reasoning for your answer.

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.)

Over the last 90 years, scientists have added to the body of evidence supporting the big bang theory. what is the latest piece of evidence discovered in 2014?

What can be found in the ionosphere