[Amy_Durante]

The compound C2Br4 (Tetrabromoethylene). The 2 and 4 together in the same compound are throwing me off. I know that it has 2 bonded pairs but what about unbonded pairs? I cannot remember what to do if there are two numbers in the same compound. 

[Terrific]

I don't believe there are any unbonded pairs in Tetrabromoethylene. Carbon forms a double bond with the other Carbon and the Bromines hang off the Carbon to form a trigonal planar geometry with a sp2 hybridization. They are all covalent bonds.

[Donaldson Tan]

The structure is similar to ethene, ie. C₂H₄. There are 6 bonding pairs (C-H and C=C) and no non-bonding pairs because all valence electron in carbon areused for bonding, and all valence electrons in H are used up in bonding.

What about the case for Bromine in C₂Br₄?

[Yggdrasil]

The compound C2Br4 (Tetrabromoethylene). The 2 and 4 together in the same compound are throwing me off. I know that it has 2 bonded pairs but what about unbonded pairs? I cannot remember what to do if there are two numbers in the same compound. 

The 2 means that there are two carbon atoms in the molecule and the 4 means that there are four bromine atoms in the molecule.  These numbers have nothing to do with the number of bonding pairs of electrons.

Try drawing a Lewis Structure of C₂Br₄ to figure out how many bonding pairs and lone (unbonded) pairs are in the molecule.