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 |
This is a fact-based question regarding the emission wavelengths of alkali metals. The correct matches based on known data 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
A body of mass 1000 kg is moving horizontally with a velocity of 6 m/s. If 200 kg extra mass is added, the final velocity (in m/s) is: