Find one element that would join (form a bond) with N-3

Zinc + lead(ii) nitrate yield zinc nitrate + leadwhat's the chemical equation for this?

Harvey mixes two liquids. which observation of the new mixture most likely indicates a precipitate is forming?

How many mmols of tris-hcl are there in 100 ml of a 100 mm tris-hcl buffer solution at ph 8.1? note that the 100 mm refers to the sum of tris and tris-hcl concentrations?