Final answer:
Fluorine (F) has the greatest number of valence electrons in its ground state out of the elements listed, with a total of seven.
Step-by-step explanation:
The element that has atoms in the ground state with the greatest number of valence electrons is fluorine (F). Both chlorine (Cl) and fluorine (F) are halogens and belong to Group 7A, meaning they have seven valence electrons in their outer shell. However, since the question specifically asks for the element in its ground state, and all of the listed elements are in their ground state by default, fluorine's ground state still has seven valence electrons, which is the greatest number among the options given. Oxygen (O) and nitrogen (N) have six and five valence electrons respectively, making them incorrect choices for this question.