The element which liberated `O_2` from water is

Oxygen is liberated from water using

Element that liberates oxygen gas from water is

X_(2) is used in the refining of Ti metal by van Arkel method Y_(2) does not liberate O_(2) from water and does not form Hy and Hoy with water x_(2) and y_(2) are respectively

Which one will liberate Br_2 from KBr.

Evidence for liberation of O_(2) from water during photosynthesis comes from