The arrangement of the electrons in an atom

1 mark · Normal

Which is the correct electronic configuration for an atom of sodium (atomic number 11)?

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Correct option: 2,8,1

Common mistakes: Misplacing electrons between shells

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Marking points

B1 · 1 mark · Selects '2,8,1' as the correct electronic configuration.

Worked solution

Sodium has 11 electrons. They are arranged: 2 in the first shell, 8 in the second, 1 in the third: 2,8,1.