Answer: C. Electrons that are available for bonding
Step-by-step explanation:
Valence Shell Electrons can be define as electrons found in the outermost shell of an atom.
These are the electrons that participate in chemical reaction.
Using the K L M electronic configuration for illustration;
Na (sodium) has 11 as its atomic number; the electronic configuration is 2, 8, 1
The last shell in a sodium atom only has 1 electron, hence we say the valence electron is 1.
This is the electron that is used in bond formation when Sodium atom reacts with other atoms of different element e.g chlorine.