Question

Potassium metal and chlorine gas react vigorously to form potassium chloride. Which statement is correct?

A. K atoms lose an electron and become Ar atoms.

B. Cl atoms gain an electron and become Ar atoms.

C. K atoms gain an electron and attain the same electron configuration as an Ar atom.

D. Cl atoms gain an electron and attain the same electron configuration as an Ar atom.

E. The K and Cl atoms change into different, more stable atoms.

Answer 1

During KCl formation

K atom loose one electron and turn into K+ ion ; which has same electron configuration of Ar

Similarly Cl atom gain an electron turns into Cl- ion. which has same electron configuration of Ar

so during KCl formation ; both atoms has same electron configuration of Ar. But they do not turn into Ar or some other atoms

so correct statement is

D. Cl atoms gain an electron and attain the same electron configuration as an Ar atom.