Answer:
a. magnesium
b. nitrogen
Explanation:
Barium and magnesium are both in 2nd group, so most similar compounds.
Nitrogen - 15 group, so it forms least similar to barium compound.
Amount of silver nitrate taken = 269.μmol 
Volume of the solution = 300. mL
Concentration of a solution is generally expressed in terms of molarity. Molarity is defined as the moles of a substance present per liter of the solution.

We want the concentration in millimoles/L.
Converting μmol to millimol solute:
μ
= 0.269 millimol
Volume from mL to L: 
Therefore concentration of the chemist's solution = 
Answer:
I'm pretty sure its a combination reaction!!
Explanation:
they generally form between metals and non metals like that^