In the following words is at end of an open syllable - radio volcano Savior nature unable?

Here's a breakdown of the syllables and whether the "o" is at the end of an open syllable:

* radio: ra-di-o (The "o" is at the end of the open syllable "di".)

* volcano: vol-ca-no (The "o" is at the end of the open syllable "ca".)

* Savior: Sa-vi-or (The "o" is at the end of the open syllable "vi".)

* nature: na-ture (The "o" is at the end of the open syllable "tu".)

* unable: un-a-ble (The "o" is at the end of the open syllable "a".)

In summary, the "o" is at the end of an open syllable in all of the words you listed.