I think the correct answers from the choices listed above are the first, third and the last option. Ionic compounds are compounds that dissociates into ions when in aqueous solution. From the list, NH4Cl, KF and MgO are the ionic compounds. Hope this answers the question.
Answer:
That involve the complete transfer of an electron from one atom of an element to another
For the first one it’s 69 just count the little lines from the side.
Answer:
The formal charge on nitrogen in
is +1.
Explanation:
The structure of
is as follows.
(In attachment)

From the structure, Nitrogen has no non bonding electrons. Nitrogen has four bonds and each bond corresponds to 2 electrons. Hence, nitrogen have eight bonding electrons and five valence electrons.
![Formal\,charge\,on\,nitrogen = 5-[0+ \frac{8}{2}]= +1](https://tex.z-dn.net/?f=Formal%5C%2Ccharge%5C%2Con%5C%2Cnitrogen%20%3D%205-%5B0%2B%20%5Cfrac%7B8%7D%7B2%7D%5D%3D%20%2B1)
Therefore, The formal charge on nitrogen in
is +1.