It is another part of name that comes after the word root. There are two types of suffixes:
- Primary Suffix
- Secondary Suffix
It is used to indicate whether the parent chain is saturated or unsaturated.
Note: If primary suffix begins with consonant like di, tri, tetra, etc. then extra “a” should be added to word root.
Number of C-atoms = 4
Word root = but
Primary suffix = 1-ene (Here, 1 is the position of double bond)
IUPAC name = word root + primary suffix
= but + 1-ene
= 1-butene (Also correct)
It is used to indicate characteristics of functional group which is added to primary suffix.