The answer would be B, an electron because the proton is positive, neutron is neutral, and the nucleus is the center of the atom.
Explanation:
The relation between
is given by :

Where :
= Ionic prodcut of water
The value of the first ionization constant of sodium sulfite = 
The value of
:


The value of the second ionization constant of sodium sulfite = 
The value of
:


Physical. you didn't burn it or create a chemical reaction
Converting mmHg to atm is solved by division.
Example: Convert 745.0 to atm.
Solution- divide the mmHg value by the 760.0 mmHg / atm.
745 mmHg over 760.0 mmHg/atm
atm value is 0.980263
Now, I am a medical student and we have never had to convert a BP (blood pressure) to atm from mmHg, only ever kPA. SO, I am going to take a guess here and say that when you do the work to solve this, you are going to convert the Systolic (upper #) which is the 145. You should get 0.190789 and then convert the Diastolic (lower #) which is 65. You should get 0.08552632.
So your fraction so to speak should read, 0.190789/0.08552632 or 0.190789 over 0.08552632
(Just to note that is way to low of a BP, although it is irrelevant) Best wishes and good luck. "Remember, never just look for the right answer, look for why it is the right answer!"
Igneous Rock because all those ingredients are in them