The number of electrons that can be held in the second orbit are 8
<h3>
Answer</h3>
HF
<h3>Explanation</h3>
A buffer solution contains <em>a weak acid</em> and<em> its conjugate base</em>. The two species shall have a similar concentration in the solution. It's also possible for <em>a weak base</em> and <em>its conjugate acid</em> to form a buffer solution.
The KF solution already contains large number of 
ions. The objective is to thus find its conjugate acid or base.
contains no proton 
and is unlikely to be a conjugate acid. Assuming that is a conjugate base. Adding one proton to would produce its conjugate acid.
Therefore 
is the conjugate acid of . happens to be a weak acid. As a result, combining with would produce a solution with large number of both the weak acid and its conjugate base, which is a buffer solution by definition.
I am pretty sure that it is called a covalent bond, I hope that I am right. If not please correct me.
