Question 1 :
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) :

Question 2 :
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 3 :
In one revolution round the hydrogen nucleus, an electron makes five crests .The electron belongs to<br>

Question 4 :
Calculate the radius of Bohr's first orbit for hydrogen atom and the energy of electron in this orbit:

Question 6 :
The ratio of $\left({E}_{2}-{E}_{1}\right)$ to $\left({E}_{4}-{E}_{3}\right)$ for the hydrogen atom is approximately equal to:

Question 7 :
According to the Bohr model of the atom, which electron transition will emit the lowest energy photon?

Question 8 :
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 9 :
A hydrogen atom in the ground state is excited by monochromatic radiation of wavelength $\lambda\ A$ The resulting spectrum consists of maximum $15$ different lines. What is the wavelength$\left( \lambda \right)$ of radiation?$ \left( Given:{ R }_{ H }=109737{ cm }^{ -1 } \right)$

Question 10 :
For any H like system, the ratio of velocities of orbit I, II &amp; III&#160; i.e.&#160;$\displaystyle V_{1}: V_{2}: V_{3}$ will be :

Question 11 :
The ionization energy of hydrogen atom is $13.6$ eV.&#160;The longest wavelength of hydrogen spectrum in&#160;the ultraviolet region is expected to be:

Question 12 :
Consider the hydrogen atom to be a proton embedded in a cavity of radius $a_0$ (Bohr's radius), whose charge is neutralized by the addition of an electron to the cavity in vacuum, infinitely slowly.&#160;Then the wavelength of the electron when it is at a distance of $a_0$ from the proton will be&#160;<br/>

Question 13 :
If elements of quantum number greater than $'n'$ were not allowed, the number of possible elements in nature would have been

Question 15 :
The wavelength($\lambda_n$) of the pion orbiting in nth stationary state is given by

Question 16 :
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 17 :
A particle of mass $m$ moves around in a circular&#160;orbit in a centro symmetric potential field u(r)$=\dfrac{kr^{2}}{2}$. Using Bohr&#8217;s quantization rule, the permissible&#160;energy levels are&#160;<br/>

Question 18 :
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 19 :
A hydrogen-like atom (atomic number $Z$) is in a higher excited state of the quantum number $n$. This excited atom can make a transition to the first excited state by successfully emitted to photons of energies $10.20eV$ and $17.00eV$ respectively.<div>&#160; &#160; &#160; &#160;Alternatively, the atom from the same excited state can make a transition to the second excites state by the successively emitting two photons of energy $4.25ev$ and $5.95ev$ respectively. Determine the values of $n$ and $Z$ (ionization energy of hydrogen atom $=13.6eV$).<br/></div>

Question 20 :
If the PE of a Bohr's hydrogen atom in the ground state is zero, then its total energy in the first excited state will be :

Question 21 :
Number of waves made by the pion when orbiting in third excitation state are

Question 22 :
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 23 :
Electrons accelerated by potential V are diffracted from a crystal. If $\mathrm{d}= 1\mathrm{A}$ and $\mathrm{i}=30^{0},\ \mathrm{V}$ should be about:&#160;<div>[$\mathrm{h}=6.6\times 10^{-34}$ Js, $\mathrm{m}_{\mathrm{e}}=9.1\times 10^{-31}$ kg, $\mathrm{e}=1.6\times 10^{-19}\mathrm{C}$]<br/></div>

Question 24 :
The only electron in the hydrogen atom resides under ordinary conditions on the first orbit. When energy is supplied, the electron moves to higher energy orbit depending on the amount of energy absorbed. When this electron returns to any of the lower orbits, it emits energy. Lyman series is formed when the electron returns the lowest orbit while Balmer series is formed when the electron returns to the second orbit. Similarly, Paschen, Brackett, and Pfind series are formed when electron returns to the third, fourth, and fifth from higher orbits, respectively.<br/>Maximum number of lines produced when an electron jumps from &#160;nth level to ground level is equal to $\displaystyle\frac{n(n - 1)}{2}$.&#160;<br/><i></i>If the electron comes back from the energy level having energy E$_2$ to the energy level having energy E$_1$, then difference may be expressed in terms of energy of photon as<br/>E$_2$ - E$_1$ = $\Delta$E, $\lambda$ = hc/$\Delta$E<br/>Since h and c are constant, $\Delta$E corresponds to definite energy, thus, each transition from one energy level to another will produce a light of definite wavelength. This is actually observed as a line in the spectrum of hydrogen atom.<br/>Wave number of line is given by the formula<br/>v = $RZ^2\left( \displaystyle\frac{1}{n_1^2} - \frac{1}{n_2^2}\right)$<br/>where R is a Rydberg constant.The wave number of electromagnetic radiation emitted during the transition of electron in between the two levels of Li$^{2+}$ ion whose principal quantum numbers sum is 4 and difference is 2 is :

Question 25 :
What is the energy required to move the electron from the ground state of H atom to the first excited state? Given that the ground state energy of H atom is 13.6 eV and that the energy E$_n$ of an electron in n$^{th}$ orbital of an atom or ion of atomic number Z is, given by the equation $E_n =(13.6Z^2/n^2)$