Answer:
um la cookie on a bar was a waste of color with climax of gdhel of
To find<span> the </span>valence electrons in an atom<span>, identify what group the element is in. An element in group 1A has 1 </span>valence electron<span>. For example, Li is in group 1A, so that means it has one </span>valence electron. If the element is in group 2A, then it has two valence electrons<span>.</span>
PH is the test of acidity or basicity of a solution. it follows the formula:
pH = pKa + log [salt] / [acid] where NaF is the salt and HF is the acid in this case.
By literature, Ka of HF is 3.5*10^-4
<span>pKa= -log(Ka)=</span><span> 3.46 </span>
<span>pH = pKa + log [NaF / [HF] </span>
4.05 = 3.46 + log [NaF / [HF]
log [NaF / [HF]<span> = 0.59
</span>
[NaF / [HF] = 3.89