The ⁴⁰₁₈X is the symbol for ⁴⁰₁₈Ar - atom and it has 18 protons, 18 electrons, and 22 neutrons.
<h3>What is Mass number ?</h3>
Mass number is the sum of the numbers of protons and neutrons present in the nucleus of an atom.
In the given element, ⁴⁰₁₈X, Subscript 18 is the number of proton and is also equal to the number of electron. While supercript 40 is the atomic mass.
The number of neutrons is given by subtracting the proton number from the mass number.
Therefore,
Number of Neutron = Mass Number - Atomic Number
= 40 - 18
= 22 Neutrons
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When a liquid goes from a liquid state to a gaseous state it is called evaporation
Answer:

Explanation:
Hello,
In this case, given the acid, we can suppose a simple dissociation as:

Which occurs in aqueous phase, therefore, the law of mass action is written by:
![Ka=\frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
That in terms of the change
due to the reaction's extent we can write:

But we prefer to compute the Kb due to its exceptional weakness:

Next, the acid dissociation in the presence of the base we have:
![Kb=\frac{[OH^-][HA]}{[A^-]}=1x10^{6}=\frac{x*x}{0.1-x}](https://tex.z-dn.net/?f=Kb%3D%5Cfrac%7B%5BOH%5E-%5D%5BHA%5D%7D%7B%5BA%5E-%5D%7D%3D1x10%5E%7B6%7D%3D%5Cfrac%7Bx%2Ax%7D%7B0.1-x%7D)
Whose solution is
which equals the concentration of hydroxyl in the solution, thus we compute the pOH:
![pOH=-log([OH^-])=-log(0.0999)=1](https://tex.z-dn.net/?f=pOH%3D-log%28%5BOH%5E-%5D%29%3D-log%280.0999%29%3D1)
Finally, since the maximum scale is 14, we can compute the pH by knowing the pOH:

Regards.