I think it’s zero, it might be zero
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO2 influx from the atmosphere into the leaves for photosynthetic carbon fixation.
Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere.
Answer: C
Explanation: The atomic mass is 22.990 so it would be C
I think its A (hope i helped)
