What point does the ammonium ions act as a buffer solution? Please this is driving me insane.

Explanation:The buffer is a mixture of ammonia (NH3) and ammonium (NH4+). ... Since ammonia (NH3) is a weak base, it will have a pH above 7 and since ammonium (NH4+) is a weak acid, it will have a pH below 7. Ammonia (NH3) is a weak base and ammonium (NH4+) is a weak acid. Ammonia (NH3) is the conjugate base of ammonium (NH4+).

Boron

Explanation:

First, locate the metalloids on the periodic table. (First picture) The metalloids are in the yellow section. Next, remember that the group your element is in determines its valence electrons. For example, group 17/7A has 7 valence electrons. Look at the group numbers above each column on the periodic table to find out which metalloid is the answer. In this case, we need to look at 13/3A since we know that this metalloid has three valence electrons. Not all  periodic tables will be labeled with the 3A part, so remember that groups 13 and over have the amount of valence electrons after you take out the one in front. For example, group 16 has 6 valence electrons because I removed the one in front of it. Now your options should be limited down to boron because we know that it is in the yellow section in group 13.