Energy Levels

Q. What is role of physics in your daily life?

Q. The rms velocity of molecule in a sample of helium gas is 5/7th of the molecules in the sample of hydrogen If the temperature of hydrogen samples is 0 degree celcius then the temperature of helium sample about :

Q. The longest wavelength in Lyman series of hydrogen atom spectrum corresponding to $H_{\alpha }$ line is approximately.

1. $1218\stackrel{\circ }{A}$
2. $216\stackrel{\circ }{A}$
3. $1016\stackrel{\circ }{A}$
4. $6578\stackrel{\circ }{A}$

Q. The energy required to take the electron from second orbit to third orbit of hydrogen atom is approximately

1. $48.5eV$
2. $10.2eV$
3. $1.9eV$
4. $13.6eV$

Q. A double charged lithium atom is equivalent to hydrogen whose atomic number is 3. The wavelength of required radiation for emitting electron from first to third Bohr orbit in $L{i}^{++}$ will be (Ionisation energy of hydrogen atom is 13.6 eV)

1. $182.51\stackrel{\circ }{A}$
2. $177.17\stackrel{\circ }{A}$
3. $142.25\stackrel{\circ }{A}$
4. $113.74\stackrel{\circ }{A}$

Q. The wavelength of the first member of Balmer series is $6563\stackrel{\circ }{A}$. Calculate the wavelength of second member of Lyman series.

1. $1025.5\stackrel{\circ }{A}$
2. $2025\stackrel{\circ }{A}$
3. $6563\stackrel{\circ }{A}$
4. None of these

Q. If the wavelength of first member of Balmer series of hydrogen spectrum is $6564\dot{A}$, the wavelength of second member of Balmer series will be:

1. $1215\dot{A}$
2. $4862\dot{A}$
3. $6050\dot{A}$
4. $5892\dot{A}$

Q. The ionization potential of the hydrogen atom is $13.6\text{volt}$. The energy required to remove an electron from the second orbit of hydrogen is:

1. $3.4\text{eV}$
2. $6.8\text{eV}$
3. $13.6\text{eV}$
4. $27.2\text{eV}$

Q. The diagram shown the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy?

1. III
2. IV
3. I
4. II

Q. The wave number of the energy emitted when electron comes from fourth orbit to second orbit in hydrogen is $20,397c{m}^{-1}$. The wave number of the energy for the same transition in $H{e}^{+}$ is

1. $5,099c{m}^{-1}$
2. $20,497c{m}^{-1}$
3. $40,994c{m}^{-1}$
4. $81,588c{m}^{-1}$

Q. Energy E of a hydrogen atom with principal quantum number n is given by $E=\frac{-13.6}{n^2}eV$. The energy of a photon
ejected when the electron jumps n = 3 state to n = 2 state of hydrogen is approximately

1. 1.9 eV
2. 1.5 eV
3. 0.85 eV
4. 3.4 eV

Q. Hydrogen atom in its ground state is excited by radiation of wavelength $975\stackrel{\circ }{A}$. How many lines will be there in
the emission spectrum

1. 2
2. 4
3. 6
4. 8

Q. A hydrogen - like atoms has one electron revolving around a stationary nucleus. The energy required to excite the electron from the second orbit to the third orbit is 47.2 eV. The atomic number of the atom is:

1. 3
2. 4
3. 5
4. 6

Q. The wavelength of radiation emitted is ${\lambda }_0$ when an electron jumps from the third to the second orbit of hydrogen atom. If the electron jumps from the fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be

1. $\frac{16}{25}{\lambda }_0$
2. $\frac{20}{27}{\lambda }_0$
3. $\frac{27}{20}{\lambda }_0$
4. $\frac{25}{16}{\lambda }_0$

Q. The wave number of the energy emitted when electron comes from fourth orbit to second orbit in hydrogen is $20,397c{m}^{-1}$. The wave number of the energy for the same transition in $H{e}^{+}$ is

1. $5,099c{m}^{-1}$
2. $20,497c{m}^{-1}$
3. $40,994c{m}^{-1}$
4. $81,588c{m}^{-1}$

Q. Every series of hydrogen spectrum has an upper and lower limit in wavelength. The spectral series which has an upper limit of wavelength equal to $18752\stackrel{\circ }{A}$ is

1. Balmer series
2. Lyman series
3. Paschen series
4. Pfund series

Q. The wave number of energy emitted when electron jumps from fourth orbit to second orbit in hydrogen in 20497 $c{m}^{-1}$. The wave number of energy for the same transition in $H{e}^{+}$ is

1. $5,099c{m}^{-1}$
2. $20,497c{m}^{-1}$
3. $40,994c{m}^{-1}$
4. $81,988c{m}^{-1}$

Q. Find the wavelength of the radiation required to excite the electron in $L{i}^{++}$ from the first to the third Bohr orbit. You may need to use the constant hc = 1242 eV.nm.

1. 13.6 nm
2. 11.4 nm
3. 27.2 nm
4. 6.8 nm

Q. In the $n^{th}$ orbit, the energy of an electron $E_n=-\frac{13.6}{n^2}eV$ for hydrogen atom. The energy required to take the electron from first orbit to second orbit will be

1. 10.2 eV
2. 12.1 eV
3. 13.6 eV
4. 3.4 eV

Q. The energy levels of a certain atom for 1st, 2nd and 3rd levels are E, $\frac{4E}{3}$ and 2E respectively. A photon of wavelength $\lambda$ is emitted for a transition $3\to 1$. What will be the wavelength of emissions for transition $2\to 1$

1. $\frac{\lambda }{3}$
2. $\frac{4\lambda }{3}$
3. $\frac{3\lambda }{4}$
4. $3\lambda$

Q. Hydrogen atom in its ground state is excited by radiation of wavelength $975\stackrel{\circ }{A}$. How many lines will be there in
the emission spectrum

1. 2
2. 4
3. 6
4. 8

Q. In the $n^{th}$ orbit, the energy of an electron $E_n=-\frac{13.6}{n^2}eV$ for hydrogen atom. The energy required to take the electron from first orbit to second orbit will be

1. 10.2 eV
2. 12.1 eV
3. 13.6 eV
4. 3.4 eV

Q. If the wavelength of the photon emitted due to transition of an electron from the third orbit to the first orbit in a hydrogen atom is $\lambda$, then the wavelength of photon emitted due to transition of an electron from the fourth orbit to the second orbit will be

1. $\frac{128}{27}\lambda$
2. $\frac{25}{9}\lambda$
3. $\frac{36}{7}\lambda$
4. $\frac{125}{11}\lambda$

Q. Energy levels A, B, C of an atom are shown below


If $E_A<E_B<E_C$, the wavelength emitted due to transistion from C to A is ${\lambda }_3$then correct statements of the following is

1. ${\lambda }_3={\lambda }_1+{\lambda }_2$
2. ${\lambda }_3=\frac{{\lambda }_1\times {\lambda }_2}{{\lambda }_2+{\lambda }_1}$
3. ${\lambda }_1+{\lambda }_2+{\lambda }_3=0$
4. ${\lambda }_3^2={\lambda }_1^2+{\lambda }_2^2$

Q. A Hydrogen atom and a $L{i}^{++}$ ion are both in the second excited state. If $l_H$ and $l_{Li}$ are their respective electronic angular momenta, and $E_H$ and $E_{Li}$ their respective energies, then

1. $l_H=l_{Li}$ and $|E_H|<|E_{Li}|$
2. $l_H=l_{Li}$ and $|E_H|>|E_{Li}|$
3. $l_H>l_{Li}$ and $|E_H|>|E_{Li}|$
4. $l_H<l_{Li}$ and $|E_H|<|E_{Li}|$