Predict the hybridization and geometry of the indicated atom

[CMATT]

Homework Statement

Predict the hybridization and geometry of the indicated atom. Answer all parts.

Homework Equations

CH₃CH₂

There is a ( - ) sign above the second C

Hybridization = ?
Geometry = ?

The Attempt at a Solution

I know I'm supposed to count the groups around the atom, but I'm stuck on that and that's the first step. By finding that out, I can determine the number of orbitals used, and then the type of hybrid orbital.

Can someone explain how to count the number of groups? The more help the better, I really do not get it.
Thanks.

 

[Borek]

What does the minus mean?

What if that was a plus?

 

[Dr Uma Sharma]

Homework Statement

Predict the hybridization and geometry of the indicated atom. Answer all parts.

Thanks.

Groups are the sigma bonds and lone pairs around the atom .Only sigma bonds and lone pairs are going to use hybridized orbitals ..sigma bonds are actually equal to number of atoms around that atom .
like in this example
CH₃ ^- in this case C has three sigma bonds with three atoms and one lone pair because of a negative charge ..so it requires four hybridized orbitals ...hence sp³
in CH₃⁺
only three sigma bonds and no lone pair ...so it is sp²