I need help with part 3 and Bonus. I don't understand. Part 1 and 2 are done. Please help with part 3 only. Thank you

Part 1. I am culturing a Nz fixing cyanobacterium and have the following media recipe for growing them: To make 1 L of salt water add the following to fresh water: 24.55g NaCl 0.75 g KCI 0.21 g NaHCO, 0.036 g HBO, 0.1157 g KBr 6.18 g MgSO4 7H2O 4.07 g MgCl 6H30 1.47 g CaCl2H20 What is the molarity of K, Na, CI, Mg, and Ca in this solution? What is the concentration of each ion (in g/kg) in this solution? Does that seem about right based on what you know about seawater? (20 points) Part 2 Now, make up 1L stock solutions of each of the following (we'll skip the vitamins): 2.94 g NaF 17.4 g SrCl26H20 6.8 g KH2PO4 0.11 g FeCl3 6H20 0.012 g ZnSO47H20 0.04 g MnCl24H20 0.027 g NazMo0.2H20 0.06 g CoCl2 6H20 0.025 g CuSO45H20 SO What is the molarity of each stock solution? Part 3. Now add 1 mL of each of the first 4 stock solutions (from part 2) to the seawater solution (from part 1). Now add 100 uL of the Zn, Mn, and Mo stock solutions (from part 2) to the seawater solution. Now add 10 uL of the Co and Cu stock solutions (from part 2) to the seawater solution. What are the final molar concentrations of each trace element in the final version of the seawater solution (F, Sr, P, Fe, Zn, Mn, Mo, Co, and Cu (in umol/L)? What is the amount of each of these constituents in g/kg? Do these concentrations seem about right? Bonus (5 points) Why is there no nitrogen in my media