In hydrogen atom, the electron makes `6.6 xx 10^(15)` revolutions per second around the nucleus in an orbit of radius `0.5 xx 10^(-10)m`. It is equivalent to a current nearly
1 Answers
Talk Doctor Online in Bissoy App
The radius of the orbit of an electron in a Hydrogen-like atom is `4.5 a_(0)`, where `a_(0)` is the Bohr radius. Its orbital angular momemtum is `(3h)
Correct Answer - A::C Angular momentum `=(nh)/(2pi)=(3h)/(2pi)implies n=3` Also `r=n^(2)/2 a_(0) implies (9a_(0))/2=3^(2)/Z a_(0) implies Z=2` For de-excitation `1/lambda=Rz^(2) [1/n_(1)^(2)-1/n_(2)^(2)]=4R[1/n_(1)^(2)-1/n_(2)^(2)]` For `n=3` to `n=1` : `1/lambda=4R[1/1-1/9] implies lambda=9/(32R)` For `n=3` to...
2 Answers 1 views
In the nth orbit, the energy of an electron `E_(n)= -( 13.6)/(n^(2)) eV` for hydrogen atom. The energy rquired to take the electron from first orbit t
Correct Answer - A For n=2, using, `E_(n)=(-13.6eV)/(n^(2))E_(2)=-(13.6)/((2)^(2))=-3.4 eV` For n=1,`E_(1)=-13.6 eV` `:. " " E_(1rarr2)=-3.4-(-13.6)=10.2ev`
2 Answers 1 views
The velocity of an electron in the first orbit of H-atom is v. The velocity of an electron in the 2nd orbit
Correct Answer - C `vprop(Z)/(n)` since Z and n both have become twice, velocity of electron in second orbit of `H^(+)` will be v.
2 Answers 1 views
Electrons are revolving around the nucleus in `n_(1^(th))` orbit of an atom, have atomic number `Z_1`, and in the `n_2` orbit of other atom, have atom
Correct Answer - A,B,D `L_1/L_2=(mv_1r_1)/(mv_2r_2)=(Z_1/n_1xxn_1^2/Z_1)/(Z_2/n_2xxn_2^2/Z_2)=n_1/n_2implies P_1/P_2(mv_1)/(mv_2)=(Z_1/n_1)/(Z_2/n_2)=(Z_1n_2)/(Z_2n_1)` `(f_1)/(f_2) =(v_1/(2pir_1))/(v_2/(2pir_2))=(Z_1/n_1xxZ_1/n_1^2)/(Z_2/n_2xxZ_2/n_2^2)=(Z_1/Z_2)^2.(n_2/n_1)^3implies (K.E._1)/(K.E._2)=(1/2mv_1^2)/(1/2mv_2^2)=(Z_1/Z_2)^2xx(n_2/n_1)^2=((Z_1n_2)/(Z_2n_1))^2` `(K.E_1)/(K.E_2)=(1/2(KZ_1e^2)/r_1)/(1/2(KZ_2e^2)/r_2)=(Z_1/n_1^2.Z_1)/(Z_2.Z_2/n_2^2)=(Z_1/Z_2.n_2/n_1)^2`
2 Answers 1 views
In an atom the ratio of radius of orbit of electron to the radius of nucleus is
Correct Answer - C The radius of orbit of electrons `=10^(-10)m` radius of nucleus `=10^(-15)m` `therefore` Ratio `=10^(-10)/(10^(-15))=10^(5)` Hence the radius of electron orbit is `10^(5)` times larger than the radius...
2 Answers 1 views
The relation between the orbit radius and the electron velocity for a dynamically stable orbit in a hydrogen atom is (where, all notations have their
Correct Answer - C In hydrogen atom electrostatic force of attraction `(F_e)` between the revolving electrons and the nucleus provides the requisite centripetal force `(F_c)` to keep them in their orbits....
2 Answers 1 views
the wavelength of radiation emitted is `lambda_0` when an electron jumps. From the third to second orbit of hydrogen atom. For the electron jumping fr
Correct Answer - B `(lambda)/(lambda_0)=([(1)/(2^2)-(1)/(3^2)])/([(1)/(2^2)-(1)/(4^2)])=(5)/(36)xx(16)/(3)=(20)/(27)`or `lambda=(20)/(27)lambda_0`
2 Answers 1 views
If `13.6eV` energy is required to separate a hydrogen atom into a proton and an electron, then the orbital radius of electron in a hydrogen atom is
Correct Answer - A Here, `E=-13.6eV=-13.6xx1.6xx10^(-19)=-2.2xx10^(-18)J` `E=(-e^2)/(8piepsilon_0r)` `therefore` As orbital radius, `r=(-e^2)/(8piepsilon_0E)=(9xx10^(9)xx(1.6xx10^(-19))^2)/(2xx(2.2xx10^(-18)))=5.3xx10^(-11)m`.
2 Answers 1 views
The radius of electron orbit and the speed of electron in the ground state of hydrogen atom is `5.30xx10^(-11)m` and `22xx10^(6)m s^(-1)` respectively
Correct Answer - D Here, `r_1=5.30xx10^(-11)m,v_1=2.2xx10^6ms^(-1)` In the second excited state, `r_n=n^2r_1,v_n=(v_1)/(n)` `therefore r_2=4r_1=4xx5.30xx10^(-11)m=2.12xx10^(-10)m` and `v_2=(v_1)/(2)=(2.2xx10^(6))/(2)ms^(-1)=1.1xx10^(6)ms^(-1)`
2 Answers 2 views
At what speed must an electron revolve around the nucleus of hydrogen atom so that it may not be pulled into the nucleus by electrostatic attraction?
Correct Answer - `2.25 xx 10^(6) ms^(-1)`
2 Answers 1 views