The candela is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency '$$A$$' $$\times 10^{12}$$ hertz and that has a radiant intensity in that direction of $$\frac{1}{{ 'B'}}$$, watt per steradian. '$$A$$' and '$$B$$' are respectively
Compare the energies of following sets of quantum numbers for multielectron system.
(A) $$\mathrm{n}=4,1=1$$
(B) $$\mathrm{n}=4,1=2$$
(C) $$\mathrm{n}=3, \mathrm{l}=1$$
(D) $$\mathrm{n}=3,1=2$$
(E) $$\mathrm{n}=4,1=0$$
Choose the correct answer from the options given below :
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 :
The incorrect postulates of the Dalton's atomic theory are :
(A) Atoms of different elements differ in mass.
(B) Matter consists of divisible atoms.
(C) Compounds are formed when atoms of different element combine in a fixed ratio.
(D) All the atoms of given element have different properties including mass.
(E) Chemical reactions involve reorganisation of atoms.
Choose the correct answer from the options given below :