How many valence electrons does a single chlorine (Cl) atom possess?

• A. 5
• B. 7
• C. 1
• D. 8

Answer: (B)

Verified step by step guidance

1. Identify the element in question, which is chlorine (Cl).
2. Determine the atomic number of chlorine, which is 17, meaning it has 17 electrons in total.
3. Recall that valence electrons are the electrons in the outermost shell (energy level) of an atom.
4. Write the electron configuration of chlorine: \$1s^2 2s^2 2p^6 3s^2 3p^5$.
5. Count the electrons in the outermost shell (the third shell): \$3s^2$ and \$3p^5$ add up to \(2 + 5 = 7\) valence electrons.