Complicated Lewis Structures

[juliasloan_4g]

I'm having a hard time knowing where to put each element with more complicated Lewis structures. For example, in question 2E19. in the seventh edition it asks for the shape and bond angles of (CH3)2Be. I drew the Lewis structure and it seemed correct. I drew it as H-C-C-Be with two more hydrogens on each Carbon. However, when I looked at the solutions manual it has it as H-C-Be-C-H. How do you know where to put each element when its not as simple as determining just one central atom?

[kamalkolluri]

A lot of the time it's written a certain way which helps you figure it out. So for example in that one, it's written (CH3)2Be. This means the CH3 group is together. and since Be forms two bonds you use intuition to know that its in the middle and connects to CH3 on each side.

[Nicoline Breytenbach 3D]

I struggle with this too, and I've found that double checking the formal charges helps me a lot.

[SydBenedict2H]

Are you referring to the [] compound's we covered in class on Monday? The coordinated compounds/bonds?