Valence shell
The number of electrons in the outermost shell of a particular atom determines its reactivity, or tendency to form chemical bonds with other atoms. This outermost shell is known as the valence shell, and the electrons found in it are called valence electrons.
Answer:
guard cells
Explanation:
they control the opening and closing of the stomata
I’m looking for this too, ain’t no way your in collage learning this.