Another possible constitutionl isomer?

[Peter2715]

I drew in another potential constitutional isomer to the right of the book answers on number 1.23, can someone explain why this does not count as an answer? Why can't the double bond be at the end right before the substituent?

See image.

[Chem_Mod]

Can you please provide a picture of what you are talking about. What you said is a little vague.

[Cindy Chen_2I]

What you draw is the same isomer as the one right next to it.
If you try to name it, you'll see that they're both named 2-Methyl-1-butene

[Peter2715]

What you draw is the same isomer as the one right next to it.
If you try to name it, you'll see that they're both named 2-Methyl-1-butene

I do see that now, since that is the case, could my drawing potentially be described as geometric isomer though? Would it be trans (E)?

[Cindy Chen_2I]

No it's still the same thing because one side of the double bond is attached to two Hs. So there would be no cis or trans in this case.
Basically you're just rotating the molecule.