If a weaker solution of sodium bicarbonate was used in beaker b, would that solution require more or less acetic acid to neutralize it? why?

Answer is: less acetic acid to neutralize it.

Balanced chemical reaction of sodium bicarbonate solution and acetic acid: NaHCO₃(aq) + CH₃COOH(aq) → CH₃COONa(aq) + H₂O(l) + CO₂(g).

According to chemical reaction: n(NaHCO₃) : n(CH₃COOH) = 1 : 1.

Stronger solution of sodium bicarbonate (NaHCO₃), more acetic acid (CH₃COOH) is neeed for neutralization.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.