6__+6___+energy from sunlight>>>_____+6______ ?

it is written that the process in the question uses energy from sunlight.

plants use energy from sunlight in photosynthesis, the process which they use to make food for themselves.

this food is in the form of glucose. meanwhile, they release oxygen, an additional product of the photosynthesis reaction, into the surroundings.

in the photosynthesis reaction, carbon dioxide and water are used to produce the glucose and oxygen.

this gives us the reactants and products in the word equation:

carbon dioxide + water (+energy from sunlight) `rarr` glucose + oxygen

to find an unbalanced chemical equation, you can simply input the chemical formulas for each compound into the equation:

`CO_2 + H_2O rarr C_6H_12O_6 + O_2`

this equation must be balanced:

both compounds on the left have a `6` before them, as shown in the question.
there are `6` `CO_2` molecules on the left side, meaning that there is also `6` `C` on the left. there must also be `6` `C` on the right.

`C_6H_12O_6` already contains `6` `C`, so there is only one `C_6H_12O_6` molecule in the reaction, for every `6` `CO_2` molecules.

if `C_6H_12O_6` is the only single molecule for `6` of every other molecule, then there are `6` of `CO_2`, `H_2O` and `O_2`.

`6CO_2 + 6H_2O rarr C_6H_12O_6 + 6O_2`