Match List-I with Match List-II
List-I (Metal)              List-II (Emitted light wavelength (nm))
(A) Li                           (I)   670.8
(B) Na                         (II)  589.2
(C) Rb                         (III) 780.0
(D) Cs                         (V)  455.5
Choose the most appropriate answer from the options given below

We need to match the alkali metals with their characteristic flame emission wavelengths.

Known flame emission wavelengths of alkali metals:

• Li (Lithium): Crimson red flame, wavelength approximately 670.8 nm
• Na (Sodium): Golden yellow flame, wavelength approximately 589.2 nm
• Rb (Rubidium): Red/violet flame, wavelength approximately 780.0 nm
• Cs (Caesium): Blue/violet flame, wavelength approximately 455.5 nm

Matching:

• (A) Li \(\rightarrow\) (I) 670.8 nm
• (B) Na \(\rightarrow\) (II) 589.2 nm
• (C) Rb \(\rightarrow\) (III) 780.0 nm
• (D) Cs \(\rightarrow\) (IV) 455.5 nm

Hence, the correct answer is Option A ((A)-(I), (B)-(II), (C)-(III), (D)-(IV)).