1) cobalt u can tell bc on a periodic table there is a small number that on cobalt is 27.
2) think that would be 11 bc in the 4th shell there can be up to 18 electrons
I think you add 29.57 + 80 and the answer would be 30.37
K + I - > KI
Potassium (needs to lose 1 electron) responds with Iodine (needs to pick up 1 electron) to fulfill both component's octet, shaping a salt, potassium iodide
This is a similar case for NaCl, simply unique components. Trust this made a difference.
Molarity = moles of solute(HCl)
------------------------------------
volume of the solution
= 1
------
5
= 0.2M.
Hence option B is correct.
Hope this helps!!