The syllable that should be accented in "chattel" is "chat".
A syllable is the smallest unit of word. Furthermore, it can influence the stress pattern in a specific word. In that way, a word can have one or two stressed syllables and more unstressed syllables.
The word "chattel" has two syllables "chat" and "tel" and it has only one stressed syllable ("chat"). It is called 'stressed syllable' to the syllable that is emphasized or pronounced louder than others. In addition, vowels in a stressed syllable are pronounced longer and at a higher pitch.
