Half life is the time that it takes for half of the original value of some amount of a radioactive element to decay.
We have the following equation representing the half-life decay:

A is the resulting amount after t time
Ao is the initial amount = 50 mg
t= Elapsed time
t half is the half-life of the substance = 14.3 days
We replace the know values into the equation to have an exponential decay function for a 50mg sample

That would be the answer for a)
To know the P-32 remaining after 84 days we have to replace this value in the equation:

So, after 84 days the P-32 remaining will be 0.85 mg
Answer:
Check the explanation
Explanation:
When,
pH = -log[H+] = 3.30
[H+] = 

![alpha[Y^-4] = [H+]^6 + Ka1[H+]^5 + Ka1Ka2[H+]^4 + Ka1Ka2Ka3[H+]^3 + Ka1Ka2Ka3Ka4[H+]^2 + Ka1Ka2Ka3Ka4Ka5[H+] + Ka1Ka2Ka3Ka4Ka5Ka6](https://tex.z-dn.net/?f=alpha%5BY%5E-4%5D%20%3D%20%5BH%2B%5D%5E6%20%2B%20Ka1%5BH%2B%5D%5E5%20%2B%20Ka1Ka2%5BH%2B%5D%5E4%20%2B%20Ka1Ka2Ka3%5BH%2B%5D%5E3%20%2B%20Ka1Ka2Ka3Ka4%5BH%2B%5D%5E2%20%2B%20Ka1Ka2Ka3Ka4Ka5%5BH%2B%5D%20%2B%20Ka1Ka2Ka3Ka4Ka5Ka6)
= 
= 
When,
pH = -log[H+] = 10.15
[H+] = 
Ka1 = 1 ; Ka2 = 0.0316 ; Ka3 = 0.01 ; Ka4 = 0.002 ; Ka5 =
; Ka6 = 
= 
= 
1) Molecular formula of ammonium sulfide
(NH4)2 S
2) That means that there are 2*4 = 8 atoms of hydrogen in each molecule of ammoium sulfide, so in 5.20 mol of molecules will be 8 * 5.20 mol = 41.6 moles of atoms of hydrogen
3) To pass to number of atoms multiply by Avogadro's number: 6.022 * 10^23
41.6 moles * 6.022 * 10^23 atoms / mol = 250.5 * 10^23 = 2.50 * 10^25 atoms
Answer: 2.50 * 10^25
Answer:
Since pH can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically
Explanation:
pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water. Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic
Answer:
95.3g
Explanation:
Given parameters:
Mass of water = 540g
Percentage by mass of solution = 15%
Unknown:
Mass of sucrose = ?
Solution;
To solve this problem, we must understand that a solution is made up of solute dissolved in a solvent. A solute is the solid dissolved in another. The solvent is the is dissolving medium;
Percentage by mass of solute in solution = 
Mass of solution = mass of water + Mass of sucrose = 540 + M
where M is the mass of sucrose;
therefore;
= 15
Solving for M gives 95.3g
Mass of sucrose is 95.3g