Answer: 72.41% and 26.90% respectively.
Explanation:
At 60°C, you can dissolve 46.4g of acetanilide in 100mL of ethanol. If you lower the temperature, at 0°C, you can dissolve just 12.8g, which means (46.4g-12.8g)=33.6g of acetanilide must have precipitated from the solution.
We can calculate recovery as:

So the answer to the first question is 72.41%.
For the second part just use the same formula, the mass of the precipitate is the final mass minus the initial mass, (171mg-125mg)=46mg.

So the answer to the second question is 26.90%.
(1) False, lots of energy is actually produced from nuclear fuel, if we didn't get much then we probably wouldn't use it
(2) False, its burning coal that contributes to acid rain, since it contains sulfur
(3) False again, we can control the reaction with aptly named control rods, which are typically made of boron, to absorb some of the neutrons flying around in the chain reaction
(4) True, radioactive waste is very difficult to dispose of, and is also very dangerous. Sources of radiation can remain so for millions of years
"Caesium" is the strongest reducing agent in Periodic table.
Hope this helps!
Answer: Edge length of the unit cell = 628pm
Explanation: For a body centred cubic structured system, the relationship between the edge length of the unit cell and radius of the atoms in the structure is
Edge length of Unit cell (a) = (4R)/(√3)
R = 272pm = (272 × (10^-12))m = (2.72 × (10^-10))m
a = (4 × (2.72 × (10^-10)))/(√3)
a = (6.28157 × (10^-10))m = 628pm