C18H38, recognized as a string of 18 simply-linked carbon atoms, like so:
H H H H H H H H H H H H H H H H H H
| | | | | | | | | | | | | | | | | |
H-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-H
| | | | | | | | | | | | | | | | | |
H H H H H H H H H H H H H H H H H H
Other forms of C18H38 are not considered octadecane, but instead are identified by naming the longest string of carbon atoms, then referencing the
branches off of them, as in 2-
methyl heptadecane, below:
H H H H H H H H H H H H H H H H H
| | | | | | | | | | | | | | | | |
H-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-H
| | | | | | | | | | | | | | | | |
H | H H H H H H H H H H H H H H H
H-C-H
|
H