The hypothesis states that the fraction of
radioactive nuclei after n half-lives is 0.5”.

in this expression, the value 0.5 represents

a) the fraction of nuclei still radioactive after any
half-life cycle.
b)the fraction of nuclei still radioactive at the
start of the experiment.
c)the amount of time it takes half of the
radioactive atoms to decay.
d)the number of half-life cycles.

If a bottle of olive oil contains 1.4 kg of olive oil, what is the volume, in milliliters ( ml ), of the olive oil?

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.)

How many atoms of mg are present in 97.22 grams of mg? 6.022 × 1023 2.408 × 1024 4.818 × 1024 5.855 × 1025