1 If the invitation says black tie, women should wear a floor-length, evening gown. 2  A tuxedo is mandatory if you're a man. 3  This is your chance to dress as if you were headed to the Oscars. 4  Black tie optional means that wearing a tuxedo or long evening gown is not mandatory, but guests should feel free to do so.
Ether is an organic functional group consisting of a disubstituted oxygen, or an oxygen atom bonded to 2 carbon atoms (if adjacent to a ketone, functional group is then called an ester).
Ether is an organic compound, or a molecule that contains carbon. Typically organic compounds have carbon chains along with other molecules, especially hydrogen. Structurally, an ether can be identified by an oxygen atom sandwiched between alkyl groups or aryl groups, in what is called an ether group.