AP Chemistryeasymcq1 pt
Which atom has the smallest first ionization energy: Li, Na, or K?
A.K
B.Li
C.Na
D.All three are equal
Explanation
Core Concept
Down a group the valence electron sits in a higher shell, farther from the nucleus and more shielded, so less energy removes it. Potassium's 4s¹ electron ionizes most easily of the three.
Correct Answer
AK
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