The ''x'' in the word equation for photosynthesis is ATP
Step-by-step explanation:
Oxygen + glucose carbon dioxide + water + x
A chemical reaction happens in this photosynthesis where the atom arrangements are changed to different arrangement to form a new substance. When during the time of photosynthesis, the energy from the Sun is stored in the form of chemical energy.
Here the X is ATP, the Adenosine triphosphate which provides energy for the plants. ATP releases small amount of energy through hydrolysis.