Answer: B, the gas is being squeezed out of the liquid.
Explanation: The gas does not want to be trapped inside of the liquid, so it is trying to force it’s way out. Therefore creating more pressure in the container or whatever the liquid is being held in.
So half life is the time taken for a sample to decay to half its original mass, its a constant and applies to any original mass, it could be 5g or 1kg, it will take the same amount of time for the original mass to half. In this case the half life is 3 days.
After 3 days the sample will be at half its original mass, now 50g.
Now we can treat the 50g as if its a new sample. After another 3 days (6 days in total) there will be half of 50g left, = 25g.
<u>Answer:</u>
(a): The balloon will contain 
number of molecules now.
(b): The gas law associated with this is Avogadro's law.
<u>Explanation:</u>
Avogadro's law states that the volume of the gas is directly proportional to the number of moles of the gas at constant pressure and temperature
Mathematically,
(At constant pressure and temperature)
OR
.....(1)
where,
= Initial volume and number of moles
= Final volume and number of moles
We are given:
Putting values in equation 1, we get:
(a):
If 
number of moles of gas contains X number of molecules
So, 
number of moles of gas will contain = 
number of molecules
Hence, the balloon will contain number of molecules now.
(b): The law used is Avogadro's law.
