AP Chemistryeasymcq1 pt
What is the formula of the ionic compound formed between potassium and sulfur?
A.K2S
B.KS
C.KS2
D.K3S
Explanation
Core Concept
Potassium, in Group 1, loses its single valence electron to become K⁺, while sulfur gains two electrons to complete its octet as S²⁻. Charge balance needs two potassium ions (+2 total) per sulfide ion (-2 total), giving K₂S.
Correct Answer
AK2S
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