Hello,
The answer is option C protons and neutrons.
Reason:
The middle of the nucleus contains the protons and the neutrons which contain the positive and electrical charges which decides the element which means option C will be your answer.
If you need anymore help feel free to ask me!
Hope this helps!
~Nonportrit
Answer : The equilibrium concentration of
in the solution is, 
Explanation :
The dissociation of acid reaction is:

Initial conc. c 0 0
At eqm. c-x x x
Given:
c = 

The expression of dissociation constant of acid is:
![K_a=\frac{[H_3O^+][C_6H_5COO^-]}{[C_6H_5COOH]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH_3O%5E%2B%5D%5BC_6H_5COO%5E-%5D%7D%7B%5BC_6H_5COOH%5D%7D)

Now put all the given values in this expression, we get:
![6.3\times 10^{-5}=\frac{(x)\times (x)}{[(7.0\times 10^{-2})-x]}](https://tex.z-dn.net/?f=6.3%5Ctimes%2010%5E%7B-5%7D%3D%5Cfrac%7B%28x%29%5Ctimes%20%28x%29%7D%7B%5B%287.0%5Ctimes%2010%5E%7B-2%7D%29-x%5D%7D)

Thus, the equilibrium concentration of
in the solution is, 
The question is incomplete, here is the complete question:
What volume (mL) of the partially neutralized stomach acid having concentration 2 M was neutralized by 0.1 M NaOH during the titration? (portion of 25.00 mL NaOH sample was used; this was the HCl remaining after the antacid tablet did it's job)
<u>Answer:</u> The volume of HCl neutralized is 1.25 mL
<u>Explanation:</u>
To calculate the volume of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of stomach acid which is HCl
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

Hence, the volume of HCl neutralized is 1.25 mL
A molecule of hydrogen is formed by two hydrogen atoms, that is a fact.
How does it work? When two atoms, known as "diatomic" pair with another in a bond known non-polar covalent bonds. Where they equally share electrons. A Hydrogen atoms needs 1 more electrons to fill its first shell fully and have a full valence shell. So if two H's share their electrons, they'll both have a full V-Shell!
That's the basics of both the H-H bond and all the other diatomic bonds as well.
<h3>
<u>ANSWER</u> </h3>
4. O²-
<h3>
<u>EXPLANATION</u> </h3>
O²- has 16 electrons while Ne has 18 electrons. O²- is a molecule that has one electron added to each atom, meaning that there are two extra electrons which makes O²- the same electron configuration as of Ne atom.