Homework question

[Grace_Stevenson_1A]

Why wouldn't this structure be Cis because the methyl and bromo group are on the same side of the double bond? Thanks!

[Alyssa Ishimoto 1A]

The structure would be trans because the ethyl on the left side of the molecule has priority and the bromo group on the right side of the molecule has priority.

[Grace_Bower_2B]

Why did you think the methyl group had higher priority than the ethyl group?
Z (cis) and E (trans) are determined base on the location of the highest priority substituent on either side. To determine priority you look at the atomic number of the molecular attached to the central carbon. In the case of methyl and ethyl it is the same; in that case, you go on more bond over and see that the methyl has a hydrogen (atomic 1) and the ethyl has a carbon (atomic 6). 6>1. Therefore the ethyl has a higher priority.
The ethyl and bromine are on opposite corners so it is Trans (E)