Question

according to the periodic table, which of these elements has atoms with the most valence electrons?
○ a. radium (ra)
○ b. argon (ar)
○ c. chlorine (cl)
○ d. potassium (k)

Explanation:

Step1: Recall valence - electron rules

Elements in group 1 have 1 valence electron, group 2 has 2 valence electrons. Elements in group 17 have 7 valence electrons and group 18 have 8 valence electrons.

Step2: Identify groups of elements

Radium (Ra) is in group 2, so it has 2 valence electrons. Argon (Ar) is in group 18, so it has 8 valence electrons. Chlorine (Cl) is in group 17, so it has 7 valence electrons. Potassium (K) is in group 1, so it has 1 valence electron.

Answer:

B. argon (Ar)