Question

What is light reaction? where does it occur in plants? Name the complete process.

Answer 1

Light reaction is the reaction which occurs in presence of light in the grana of chloroplast.

The process:
First the chlorophyll absorbs photons and get activated....and then water is split into H+ ions, electrons and oxygen gas.

2H2O ----> 4H+ + 4e + O2

Answer 2

There are two types in this reaction.
Light dependent reaction and
Light independent reaction.
the chlorophyll on exposure to light energy becomes activated by absorbing photos (photon is the smalest unit of light energy )
the energy is used on splitting the water molecule into two component ions named hydrogen H+and hydroxyl ionOH_.
H2O gives rise to H+OH
the highly reactive ions of water undergo quick change.