For each of the following compounds, draw the Lewis dot structure for...?

Question

all non-metallic compounds and draw
the molecular model for any metallic compounds. Tell what kinds of bonds form (pure covalent, polar
covalent, ionic, or metallic), and indicate whether or not there is a resonance hybrid.

CIF3
NO3-1
Ca
MgO
F2

I have no problem with NO3-1, F2, or ClF3.

But I can't figure out what to do with MgO at all, and before I get all the people yelling at me, yes I have been through my text book and everything I can find on the web.

My other issue is Ca. Isn't Ca an atom and not a compound? If it is a compound how does that work?

Answer 1

Everything you drew is neutral (except for NO3-). So for those to be neutral, they have to their positive and negative charges balancing. Mg has an oxidation state of 2+ where oxygen has 2-. Because it is an ionic bond, the oxygen gives its electrons to the deficient Mg. So the structure would have oxygen with 8 electrons (6 valence + 2 from charge) and Mg would have 0 electrons (2 in valence but missing 2 because of charge).

Ca metal has 2 valence electrons (from the peroiodic chart) so its structure would be Ca with 2 "dots".

Answer 2

i was taught S=N-A which is: S is the shared electrons N is the needed electrons A is the available electrons so in a) for example: S=(8+8)-(7+7) S=16-14 so the shared electrons is 2. BrF forms a single bond and when u dot the rest of the electrons, they should add up to 14 hopefully this helped

Answer 3

For Ca, the only thing to do is to draw ** on one side for its two valence electrons.

For MgO, put ** and xx between the Mg and the O. The xx are the two valence electrons of Mg. Next put two more sets of ** on two sides of O. These are the nonbonding electrons of O.