How many valence electrons does a potassium (K) atom have?

• A. 1
• B. 8
• C. 2
• D. 7

Answer: (A)

Verified step by step guidance

1. Identify the element in question, which is potassium (K).
2. Determine the atomic number of potassium, which is 19, meaning it has 19 electrons in a neutral atom.
3. Recall that valence electrons are the electrons in the outermost shell (energy level) of an atom.
4. Write the electron configuration of potassium: \$1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{1}$.
5. From the electron configuration, observe that the outermost shell is the 4th shell with only one electron in the 4s orbital, so potassium has 1 valence electron.