Multiple Choice
Which of the following is the number of valence electrons in a neutral atom of selenium (Se)?
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10. Periodic Properties of the Elements
Valence Electrons of Elements
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
How many valence electrons does a potassium (K) atom have?
A
1
B
8
C
2
D
7
Verified step by step guidance1
Identify the element in question, which is potassium (K).
Determine the atomic number of potassium, which is 19, meaning it has 19 electrons in a neutral atom.
Recall that valence electrons are the electrons in the outermost shell (energy level) of an atom.
Write the electron configuration of potassium: $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 4s^{1}$.
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.
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