[Agent-X]

In a previous thread, someone wrote this about alkenes:

For disubstituted olefins, it's ok to say that if they're on the same size, it's cis.  and if they're on the opposite side, they're trans.  cis/trans are really most appropriate for disubstituted olefins.  you should change to E/Z for tri and tetrasubstituted olefins.

I have the molecule 2-methyl-2-butene:

(CH₃)₂C=CHCH₃

Shouldn't I consider this molecule cis(Z)-2-methyl-2-butene?
Should it plainly be read as "2-methyl-2-butene"?

If I were to pickup a book and read "2-methyl-2-butene," I could visualize the molecule; but why is it not named cis-2-methyl-2-butene or Z-2-methyl-2-butene?

[orgoclear]

The compound that you have drawn  will not show geometrical isomerism because the two substituents attached to the C-atom are the same. So if you rotate the molecule about the double bond, you won't get a different compound (stereochemically). Hence you can't apply cis/trans or E/Z here

[Agent-X]

The compound that you have drawn  will not show geometrical isomerism because the two substituents attached to the C-atom are the same. So if you rotate the molecule about the double bond, you won't get a different compound (stereochemically). Hence you can't apply cis/trans or E/Z here

Thank you for your reply.
I understand.