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.
<em>limestone</em>
<em>The most common chemical sedimentary rock, by far, is limestone . Others include chert , banded iron formation , and evaporite</em><em>s</em><em>.</em>
•move
•maintain homeostasis
•require and use energy
•respond to stimuli
•reproduce
•grow and develop
•display organization
•made up of one or more cells
