Question

Match List-I with List-II.

List-I Alkali Metal	List-II Emission Wavelength in nm
(A) Li	(I) 589.2
(B) Na	(II) 455.5
(C) Rb	(III) 670.8
(D) Cs	(IV) 780.0

Choose the correct answer from the options given below:

• A. (A)-(I), (B)-(IV), (C)-(III), (D)-(II)
• B. (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
• C. (A)-(IV), (B)-(II), (C)-(I), (D)-(III)
• D. (A)-(II), (B)-(IV), (C)-(III), (D)-(I)

Answer 1

The Correct Option is B

To address this issue, we must correlate the alkali metals presented in List-I with their respective emission wavelengths detailed in List-II. Alkali metals are recognized for their distinct flame colors upon excitation, which are directly linked to specific light wavelengths emitted during electronic transitions. The emission wavelengths for each metal are as follows:

1. Lithium (Li) emits a red light with an approximate characteristic emission wavelength of 670.8 nm, corresponding to option (III).
2. Sodium (Na) produces a vivid yellow flame with a wavelength of 589.2 nm, matching option (I).
3. Rubidium (Rb) displays a reddish-violet flame with an emission wavelength of approximately 780.0 nm, correlating with option (IV).
4. Cesium (Cs) exhibits a violet-blue flame with an associated emission wavelength of 455.5 nm, aligning with option (II).

Based on this analysis, the corresponding matches between metals and their wavelengths are:

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

Consequently, the correct pairing is: (A)-(III), (B)-(I), (C)-(IV), (D)-(II).