The shortest wavelength of H-atom in Lyman series is x, then longest wavelength in Balmer series of `He^(+)` isA. `(4)/(3)`B. `(36)/(5)`C. `(1)/(4)`D. `(5)/(9)`

The shortest wavelength of H-atom in Lyman series is x, then longest w

1.	The shortest wavelength of H-atom in Lyman series is x, then longest wavelength in Balmer series of `He^(+)` isA. `(4)/(3)`B. `(36)/(5)`C. `(1)/(4)`D. `(5)/(9)`
Answer» Correct Answer - A (a) Longest wavelength in Lyman Series of hydrogen atom arisis from transition between `n = 2` to `n = 1` whose number is given by `overline v_(H(2rarr1)) = R xx 1^2 ((1)/(1^2) - (1)/(2^2)) = (3)/(4) R` Shortest wavelength in Balmer series of `He^+` arises from transition between `n = a` to `n = 2` whose wave number is given by `overline v_(He(alpha -2)) = R xx 2^2 ((1)/(2^2) -(1)/(alpha^2)) = R` =`(overlinev_(He))/(overlinev_H) = (lamda_H)/(lamda_(He))` `:. (lamda_H)/(lamda_(He)) = (4R)/(3R) = (4)/(3)`.

Discussion

No Comment Found

Related InterviewSolutions

The ratio between the neutrons present in nitrogen atom and silicon atoms with number 14 and 28 is :A. `7:3`B. `3:7`C. `1:2`D. `2:1`
Which one of the following sets of ions represents the collection of isoelectronic species?A. `Na^(+),Mg^(2+),Al^(3+),Cl^(-)`B. `Na^(+),Ca^(2+),Sc^(3+),F^(-)`C. `K^(+),Cl^(-),Mg^(2+),Sc^(3+)`D. `K^(+),Ca^(2+),Sc^(3+),Cl^(-)`
If `I_(0)` is the threshold wavelength for photoelectric emission, 1 the wavelength of light falling on the surface of a metal and m is the mass of the electron, then the velocity of ejected electron is given byA. `[(2h)/(m)(lambda - lambda)]^(1//2)`B. `[(2hc)/(m)(lambda_(0)-lambda)]^(1//2)`C. `[(2hc)/(m){(lambda_(0)-lambda)/(lambda lambda_(0))}]^(1//2)`D. `[(2hc)/(m){(1)(lambda_(0))-(1)/(lambda)}]^(1//2)`
If the threshold wavelength `(lambda_(0))` for spection of electron from metal is `350nm `then work function for the photoelectric emission isA. `1.2 xx 10^(-18) J`B. `1.2 xx 10^(-20) J`C. `6 xx 10^(-29) J`D. `6 xx 10^(-12) J`
Which one of the following sets of ions represents a colloection of isoelectronic species ?A. ` K^+ , Cl^- , Ca^(2+) , Sc^(3+)`B. ` K^+ , Cl^- , Ca^(2+) , Sc^(2+), Sc^(3+)`C. `N^(3-), O^(2-) F^- , S^(2-)`D. `Li^+ , Na^+ , Mg^(2+) , ca^(2+)`.
If `lambda_(0)` is the threshold wavelength for photoelectric emission. `lambda` wavelength of light falling on the surface on the surface of metal, and `m` mass of electron. Then de Broglie wavelength of emitted electron is :-A. `[(h(lambdalambda_(0)))/(2mc(lambda_(0)-lambda))]overset(1)(2)`B. `[(h(lambda_(0)-lambda))/(2mclambdalambda_(0))]overset(1)(2)`C. `[(h(lambda-lambda_(0)))/(2mclambdalambda_(0))]overset(1)(2)`D. `[(hlambdalambda_(0))/(2mc)]overset(1)(2)`
If the threshold wavelength `(lambda_(0))` for ejection of electron from metal is `350 nm ` then work function for the photoelectric emission isA. `1.2 xx 10^-18 J`B. `1.2 xx 10^-20 J`C. `6 xx 10^-19 J`D. `6 xx 10^-12 J`
Elements up to atomic number `103` have been synthesized and studied. If a newly discovered element is found to have an atomic number `106`, its electronic configuration will beA. `[Rn]5 f^14 , 6d^4, 7s^2`B. `[Rn]5 f^14 , 6d^1, 7s^2 7p^3`C. `[Rn]5 f^14 , 6d^6, 7s^0`D. `[Rn]5 f^14 , 6d^5, 7s^1`
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [`a_0` is Bohr radius] :A. `(h^(2))/(4 pi^(2) ma_(0)^(2))`B. `(h^(2))/(16 pi^(2) ma_(0)^(2))`C. `(h^(2))/(32 pi^(2) ma_(0)^(2))`D. `(h^(2))/(64 pi^(2) ma_(0)^(2))`
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [`a_0` is Bohr radius] :A. `h^2/(4pi^2 ma_0^2)`B. `h^2/(16pi^2 ma_0^2)`C. `h^2/(32pi^2 ma_0^2)`D. `h^2/(64pi^2 ma_0^2)`

The shortest wavelength of H-atom in Lyman series is x, then longest wavelength in Balmer series of `He^(+)` isA. `(4)/(3)`B. `(36)/(5)`C. `(1)/(4)`D. `(5)/(9)`

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment