Cis vs Trans

[Donavin Collins 1F]

What's the difference between cis and trans in chemistry? I've seen it around (like cisplatin and transplatin) but haven't really covered it yet.

[Chem_Mod]

Not necessary to know for this class but in an alkene, ie HCH3C=CCH3H, cis has the identical attachments on the carbons on the same side, trans has them on opposite sides

[Daniel Toscano 1L]

cis means the same ligands are on the same side while trans means the same ligands are across from each other, separated by the central atom.
The terms tell us about the compound's geometry

[Sydney Pell 2E]

An example of this that was used in class is cisplatin and transplatin. In cisplatin, the Cl atoms are on one side of the central Pt and the NH3 molecules are bonded the opposite side. In transplatin, one Cl and one NH3 switch places so that the Cls and NH3s are diagonal from each other instead of side-by-side.