Answer:
I think the answer would be b, sorry if I'm wrong(EDIT: ITS ACTUALLY AAAAA)
This question is asking for an element with 5 valence electrons. Just go to the row it is in (excluding transition metals) and count over.
The answer would be c. P
Answer:
D. when the number of moles of acid is exactly equal to the number of moles of base.
Explanation:
<em>Regarding options A. and E</em>., pKa and pKb would only be taken into consideration if the titrations were of <em>weak</em> acids and bases. However it is possible to have a titration of monoprotic acids and bases with strong acids and bases.
Another way of looking at the answer is identifying <em>which one best describes the equivalence point</em>.