Isotopes of oxygen

There are three known stable isotopes of oxygen (₈O): ¹⁶
O
, ¹⁷
O
, and ¹⁸
O
.

Radioactive isotopes ranging from ¹¹
O
to ²⁸
O
have also been characterized, all short-lived. The longest-lived radioisotope is ¹⁵
O
with a half-life of 122.266(43) s, while the shortest-lived isotope is the unbound ¹¹
O
with a half-life of 198(12) yoctoseconds, though half-lives have not been measured for the unbound heavy isotopes ²⁷
O
and ²⁸
O
.