There are so many things wrong with this.
"An unabomber" is incorrect, as the "u" in "unabomber" is acting
like "y" as a consonant, and therefore it should read "a
unabomber".
However, that doesn't really matter because "Unabomber" is a
proper noun, referring to either the domestic terrorist Theodore
Kaczynski or the poker player Phil Laak. It should read "The
Unabomber", not "a unabomber".
"11" should have a "th", signifying the word "eleventh", and not
the number "eleven".
Finally, even though it is punctuated with a question mark, that
is only a fragmented sentence. "Does anyone have an essay about The
Unabomber to give to an 11th grader?" is the implied query, which
brings me to my final answer: Do your own work, brat.