Answer:
I think the answer is B or Compounds
<u>Answer:</u> The half life of the sample of silver-112 is 3.303 hours.
<u>Explanation:</u>
All radioactive decay processes undergoes first order reaction.
To calculate the rate constant for first order reaction, we use the integrated rate law equation for first order, which is:
![k=\frac{2.303}{t}\log \frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%20%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 1.52 hrs
= Initial concentration of reactant = 100 g
[A] = Concentration of reactant left after time 't' = [100 - 27.3] = 72.7 g
Putting values in above equation, we get:

To calculate the half life period of first order reaction, we use the equation:

where,
= half life period of first order reaction = ?
k = rate constant = 
Putting values in above equation, we get:

Hence, the half life of the sample of silver-112 is 3.303 hours.
The answer is hard to give without any information.
Owls means a mammalian species
It is incorrect question
Answer : The correct option is, (b) 22.1 g
Solution : Given,
Mass of iron = 15.5 g
Molar mass of iron = 56 g/mole
Molar mass of
= 160 g/mole
First we have to calculate the moles of iron.

Now we have to calculate the moles of
.
The balanced reaction is,

From the balanced reaction, we conclude that
As, 2 moles of iron obtained from 1 mole of 
So, 0.276 moles of iron obtained from
mole of 
Now we have to calculate the mass of 

Therefore, the amount of
required are, 22.1 grams.