Question 1 • Chemistry Honors A
The configuration lists every occupied subshell for potassium: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹. Writing out all the subshells is called longhand notation. Noble-gas notation would replace the filled inner shells with [Ar], giving [Ar] 4s¹, so choice A, longhand notation, is correct.
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