CBSE
Multiple Choice QuestionsAssertion: In a metal all the free electrons have same energy.
Reason: : Electrons do not obey Pauli's Exclusion principle
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true and reason is false
If both assertion and reason are false
What would be maximum wavelength for Brackett series of hydrogen-spectrum?
74589 Ao
22790 Ao
40519 Ao
18753 Ao
The series corresponding to minimum wavelength transition in H-atom
Balmer series
Lyman series
Paschen series
Brackett series
The wavelength of Lyrnen series for first number
is
m
m
m
× 1.097 × 107 m
What is the energy of He+ electron in first orbit?
40.8 eV
-27.2 eV
-54.4 eV
-13.6 eV
The wavelengths of Kα X- rays for lead isotopes Pb208 , Pb206 and Pb204 are λ1, λ2 and λ3 respectively. Then
λ2 =
λ2 = λ1 + λ3
λ2 = λ1 λ2
λ2 =
Assertion: It is essential that all the lines available in the emission spectrum will also be available in the absorption spectrum.
Reason: The spectrum of hydrogen atom is only absorption spectrum.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Energy required to break one bond in DNA is approximately
∼ 1 eV
∼ 0.1 eV
∼ 0.01 eV
∼ 2.1 eV
The ground state energy of hydrogen atom is -13.6 eV. What is the potential energy of the electron in the state?
0 eV
-27.2 eV
1 eV
2 eV
What would be the radius of second orbit of He+ ion?
1.508 Ao
3.023 Ao
2.068 Ao
4.458 Ao
