text: give the iupac name for....? (ch3)2c(ch2ch3)c=cch(ch3)2  "=" this symbol actually depicts a triple bond 2,5,5-trimethyl-3-heptyne or 2,5,5-trimethylhept-3-yne  the ethyl group is what makes it tricky - because that actually becomes part of the backbone chain.  look at it this way:  c-c-c(ch3)2-c≡c-c(ch3)-c