Select correct statement:
The ideal body, which emits and absorbs all frequencies, is called a black body.
The exact frequency distribution of the emitted radiation from a black body depends upon its temperature.
The radiation emitted goes from a lower frequency to a higher frequency are correct statements
All of the above are correct statements
Threshold energy is also called:
Work function
Potential energy (PE)
Kinetic energy(KE)
Sum of (PE) and (KE)
If in Moseley’s equation, given constants a=b =1, then for the frequency v = 400 s-1, elements will be:
K
Na
Rb
Cs
Number of waves made by a Bohr electron in one complete revolution in its fourth orbit is:
2
3
4
(
An electron in H-atom in its ground state absorbs, 1.50 times as much as energy as the minimum required for its escape (13.6ev) from the atom. Thus KE given to emitted electron is:
13.6ev
20.4ev
34.0ev
6.8ev
Which of the following electronic transitions requires that the greatest quantity of energy be absorbed by a hydrogen atom?
n = 1 to n =2
n =2 to n =4
n =3 to n =6
n =1 to n =(
Electron falls from seventh energy level and lower energy level to give bands in Paschen series. Total number of bands obtained are:
4
3
2
1
The total energy of an electron in the first Bohr orbit in the He+ ion is:
- 13.6ev
-27.2ev
-54.4ev
-6.8ev
‘Hartree is the atomic unit of energy and is equal to:
-13.6eV atom-1
-27.12eV atom-1
+ 54.4eV atom-1
+ 13.6eV atom-1
A continuum is spectrum is observed due to the following:
Once and electron is completely free from the nuclear it is no longer restricted to quantized discrete energy states
Electron takes up continuously the ordinary kinetic energy corresponding to its speed in free space
Both the reasons are correct
None of the two reasons are correct