Question

the diagram shows the electron configuration around the chlorine nucleus. chlorine has 17 protons

which of the following correctly completes the statement?

chlorine has ____ valence electrons, and the effective nuclear charge, ( z_{e f f} ), for the chlorine atom shown is ____

7, 7+
17, 7+
10, 7-
7, 7-

Explanation:

Step1: Determine the number of valence electrons

Valence electrons are the electrons in the outermost shell. Chlorine has 7 electrons in its outermost shell.

Step2: Calculate the effective nuclear charge

The formula for effective nuclear charge \(Z_{eff}=Z - S\), where \(Z\) is the atomic number (number of protons, \(Z = 17\)) and \(S\) is the number of shielding electrons. For chlorine, the number of shielding electrons \(S=10\) (2 in the first shell and 8 in the second shell). So \(Z_{eff}=17 - 10=7+\)

Answer:

7; 7+