Question

what element is described by the illustration?
sodium (na)
oxygen (o)
argon (ar)
chlorine (cl)

Explanation:

The atomic number (number of protons) is shown as 17. Chlorine (Cl) has an atomic number of 17. Sodium (Na) has atomic number 11, Oxygen (O) has atomic number 8, and Argon (Ar) has atomic number 18.

Answer:

Chlorine (Cl)