Question 1 : <p>The maximum wavelength of light that can excite an electron from first to the third orbit of a hydrogen atom is : </p>

Question 2 : The Bohr's radius for the fifth orbit of the hydrogen atom will be:

Question 5 : A small particle of mass $m$ moves in such a way that $P.E=-\displaystyle \frac{1}{2}mkr^{2}$, where $k$ is a constant and $r$ is the distance of the particle from origin. Assuming Bohr's model of quantization of angular momentum and circular orbit, $r$ is directly proportional to:

Question 7 : The two electrons have the following sets of quantum numbers.<br/>X: 3, 2, -2, +1/2<br/>Y: 3, 0, 0, + 1/2<br/>What is true of the following?

Question 8 : The Bohr orbit radius for the hydrogen atom $(n = 1)$ is approximately $0.530 \mathring{A}$ The radius for the first excited state $(n = 2)$ will be:

Question 9 : The ratio of the difference in energy between the first and the second Bohr orbit to that between the second and the third Bohr's orbit is:<br/>

Question 10 : If first ionisation energy of hydrogen is $E$, then the ionisation energy of ${ He }^{ + }$ would be:

Question 12 : Not considering the electron spin, the degeneracy of second excited state is 9, while the generality of the first excited state of $H$ atom is:&#160;

Question 13 : The ratio of the momentum of a proton and a&#160;$\alpha $ - particle which is accelerated from rest by a potential difference of 200 V.&#160;$m_{p}$ and $m_{\alpha }$ are masses of the proton and ${\alpha }$- particles:&#160;

Question 14 : <div>A formula analogous to the Rydberg formula applies to the series of spectral lines which arise from transitions from higher energy level to the lower energy level of hydrogen atom.<br/>A muonic hydrogen atom is like a hydrogen atom in which the electron is replaced by a heavier particle, the 'muon'. The mass of the muon is about $207$ times the mass of an electron, while the charge&#160;remains same as that of the electron. Rydberg formula for hydrogen atom is:<br/>$\dfrac { 1 }{ \lambda &#160;} ={ R }_{ H }\left[ \dfrac { 1 }{ { n }_{ 1 }^{ 2 } } -\dfrac { 1 }{ { n }_{ 2 }^{ 2 } } &#160;\right] \left( { R }_{ H }=109678{ cm }^{ -1 } \right) $<br/></div>Radius of first Bohr orbit of muonic hydrogen atom is

Question 15 : The energy of the second Bohr orbit in the hydrogen atom is $-3.41\ eV$. The energy of the second Bohr orbits of $He^+$ ion would be:

Question 16 : For the energy levels in an atom which one of the following statements is(are) correct?

Question 17 : An electron in a hydrogen atom in its ground state absorbs energy equal to the ionization energy of $Li<br/>^{{\text{ + 2}}} <br/>$. The wavelength of the emitted electron is:<br/>

Question 18 : For the hydrogen atom, the energy of the electron in the $n$th orbit is given by $E=\dfrac{-13.6}{n^{2}}\ eV$, where $n$ is an integer. The smallest amount of energy that a hydrogen atom can absorb in its ground state is:

Question 19 : The velocity of electron in third excited state of $\displaystyle Be^{3+}$&#160;will be:

Question 20 : The energy of an electron in the $3s$ orbital (excited state) of H-atom is:&#160;

Question 21 : For which of the following, the radius will be same as for hydrogen atom having $n=1$?

Question 22 : In a hydrogen atom, an electron jumps from the third orbit to the first orbit. Find out the frequency of the spectral line. $\left( { R }_{ H }=1.09678\times { 10 }^{ 7 }{ m }^{ -1 } \right) $.

Question 23 : In one revolution round the hydrogen nucleus, an electron makes five crests .The electron belongs to<br>

Question 24 : If m and e are the mass and charge of the revolving electron in the orbit of radius r for hydrogen atom, the total energy of the revolving electron will be:

Question 26 : <div>Assertion (A): Hydrogen has one electron in its orbit but it produces several spectral lines.</div><div>Reason (R): There are many excited energy levels available.<br></div>

Question 27 : The ratio of the difference in energy between the first and second Bohr orbits to between the second and third Bohr orbit is:

Question 28 : Which of the following parameters are same for all hydrogen like atoms and ions in their ground state?

Question 30 : If the radius of second stationary orbit (in Bohr's atom) is R. Then, the radius of third orbit will be:

Question 31 : &#160;Bohr's radius for the fifth orbit of the hydrogen atom in $A^0$ is :

Question 32 : In the hydrogen atom an electron is moving in nth orbit. The circumference s of the orbit and the de Broglie wavelength, of the moving electron are related by the equation

Question 33 : Which one of the following sets of quantum numbers represents the highest energy level in an atom?<br/>

Question 34 : Which of the following electron transition in hydrogen atom will require the largest amount of energy?

Question 35 : Consider a hypothetical hydrogen like atom. The wavelength in $A^o$ for the spectral lines for transition from $n=p$ to $n=1$ are given by:<br/>$\lambda =\displaystyle\frac{1500p^2}{p^2-1},$ where $p &gt; 1$<br/>Find the ionization potential of this element?<br/>

Question 36 : The total energy of an electron in the ground state of the hydrogen atom is -13.6 eV. The kinetic energy of an electron in the first excited state is:<br/>

Question 37 : According to de-Broglie wavelength for electron in an orbit of hydrogen atom is $10^{-9}\ m$. The principle quantum number for this electron is

Question 38 : The possible subshells in $n = 3$ energy shell are :

Question 39 : Out of given atoms which atoms has highest energy of 2s-subshell ?

Question 41 : If the ionization energy for hydrogen atom is $13.6 eV$, then the ionization energy for ${He}^{+}$ ion should be:

Question 42 : If the ionization energy of hydrogen is $313.8 \; {Kcal}/{mol}$, then the energy of electron in ${2}^{nd}$ excited state will be:

Question 43 : The ionization enthalpy of hydrogen atom is $1.312\times 10^{6}\ \mathrm{J}$ mol$^{-1}$. The energy required to excite the electron in the atom from $\mathrm{n}=1$ to $\mathrm{n}=2$ &#160;is&#160;:&#160;<br/>

Question 44 : The wavelength of the radiation emitted, when in a hydrogen atom electron falls from infinity to stationary state, would be: [Rydberg constant = $1.097\times { 10 }^{ 7 }\ { m }^{ -1 }$]

Question 45 : By what percent does the distance between successive orbits of 1 and 2 to 2 and 3 of hydrogen atom vary?

Question 46 : A particle of mass M at rest decays into two particles of masses $m1$ and $m_2$, havung non-zero velocities. The ratio of the de-Broglie wavelengths of the particles, $l_1/l_2$ is?

Question 47 : The angular speed $(\omega)$ of an electron revolving in $n^{th}$ Bohr orbit and corresponding principal quantum number(n) are related as ____________.

Question 48 : In an atom the shell which has a maximum two electrons is:

Question 49 : The ionisation energy for the H atom is 13.6 eV then the requried energy in eV to excite it from the ground state to next higher state will be (in eV)&#160;:

Question 50 : According to the Bohr model of the atom, which electron transition will emit the lowest energy photon?

Question 51 : If the wavelength of the photon emitted from an electron jump n $=$ 4 to n $=$ 2 in a H-like species is 1216 $\overset{o}{A}$, then the species is :

Question 52 : Assertion: 3s, 3p and 3d subshells of hydrogen have the same energy. <br/>Reason: Energy of subshells in the hydrogen atom, depends on the principal quantum number (n) and azimuthal quantum number (l).&#160;<br/>

Question 53 : If elements of quantum number greater than $'n'$ were not allowed, the number of possible elements in nature would have been

Question 54 : The total energy of a hydrogen atom in its ground state is $-13.6\ eV$. If the potential energy in the first excited state is taken as zero then the total energy in the ground state will be:

Question 57 : The energy of the second Bohr orbit in the hydrogen atom is $-3.41 \,eV.$ The energy of the second Bohr orbit of $He^{+}$ ion would be:

Question 58 : The longest wave length radiation emitted in the emission spectrum when the pion de-excites from n = 3 to ground state lies in which of the following region?

Question 59 : <div>For $H$-like atoms :</div><div>&#160; &#160; &#160;&#160;</div><div>&#160; &#160; &#160; &#160; &#160; &#160; $\displaystyle E_n=-\frac{Z^2Rh}{n^2};u_n=\frac{u_1Z}{n}$ and $r_n=\frac{r_1\times n^2}{Z};$ where $Rh$ is Rydberg.<br/></div><br/>What is the potential energy of electron in $2^{nd}$ orbit of $H$-atom?<br/>

Question 60 : The number of revolutions of an electron in the second Bohr orbit in one second is:<br>