Bohr's Model of a Hydrogen Atom

Q. maximum number of orbitals in p shell is a.3 b.6 c.18. d.36

Q. which d-orbital is involved in sp3d hybridisation

Q.

In a hydrogen atom, the electron makes a transition from (n + 1)^th level to the nth level. If n>>1, the frequency of radiation emitted is proportional to:

1. 1/n²

2. 1/n

3. 1/n³

4. 1/n⁴

Q. In the Balmer series of the hydrogen spectrum, the third line corresponds to which one of the following inter-orbit jumps of the electron:

1. $5\to 2$
2. $4\to 1$
3. $2\to 5$
4. $3\to 1$

Q. calculate the minimum and maximum wavelength of lyman series

Q.

In Hydrogen, the energy of an electron is determined solely by principal quantum number (n).

1. False

2. True

Q.

Which one of the following is not a valid value for the magnetic quantum number of an electron in a 5d sub shell?

1. 1

2. 2

3. 3

4. 5

Q. Bohr's theory is applicable to which of the following set of species?

1. $H^{+},H{e}^{2+},L{i}^{3+},B{e}^{4+}$
2. $H,H{e}^{+},L{i}^{2+},B{e}^{3+}$
3. $H^{+},L{i}^{+},H{e}^{+},B{e}^{+}$
4. For all these sets

Q. Energy of a photon with a wave length of $450nm$ is

1. 4.36 X 10^-12 ergs

2. 4.36 X 10^-13 ergs

3. 4.36 X 10^-20 ergs

4. 4.36 X 10^-11 ergs

Q.

According to Bohr model of hydrogen atom, the radius of stationary orbit characterized by the principal quantum number n is proportional to

Q. Calculate the ratio of the speed of light and the speed of electron in the first Bohr orbit of a hydrogen atom.

1. 137
2. 138
3. 139
4. 140

Q.

The frequency of the spectral line obtained when the electron in n = 3 of hydrogen atom drops to the ground state is:

1. 2.925 X 10¹⁵ Hertz

2. 2.925 X 10¹³ Hertz

3. 2.925 X 10¹⁴ Hertz

4. 36559 X 10¹⁰ Hertz

Q. Going from K shell to N shell, how can KE decrease as on going farther away from the nucleus the electron rotates faster due to lesser hold of the nucleus?

Q. If the radius of second Bohr's orbit of hydrogen atom is $r_2$ then the radius of third Bohr's orbit of $B{e}^{3+}$ ion will be:

1. $9r_2$
2. $\frac{9r_2}{8}$
3. $\frac{9r_2}{16}$
4. $\frac{9r_2}{4}$

Q. how molecular orbitals are formed by addition and subtraction overlap

Q.

The simplest ion of Pyro-silicates is:

1. 

2. 

3. 

4. 

Q. The radius of hydrogen atom in ground state is $0.53\stackrel{\circ }{A}$. The radius of the first orbit of$L{i}^{2+}$ will be:

1. $1.27\stackrel{\circ }{A}$
2. $0.18\stackrel{\circ }{A}$
3. $0.57\stackrel{\circ }{A}$
4. $0.99\stackrel{\circ }{A}$

Q. Which of the following is not among shortcomings of Bohr’s model Which of the following is not among shortcomings of Bohr’s model? a) Bohr theory could not account for the fine lines in the atomic spectrum b) Bohr theory was unable to account for the splitting of the spectral lines in the presence of magnetic field c) Bohr theory failed for He atom d) It did not give information about energy level explain in detail the reason

Q. Hydrogen atoms in a particular excited state 'n', when all returned to ground state, 6 different photons are emitted. Which of the following is/are incorrect?

1. Out of 6 different photons, only 2 photons have speed equal to that of visible light.
2. If highest energy photon emitted from the above sample is incident on the metal plate having work function 8 eV, KE of liberated photo-electron may be equal to or less than 4.75 eV.
3. Total number of radial nodes in all the orbitals of $n^{th}$ shell is 14.
4. Total number of angular nodes in all the orbitals in $(n-1{)}^{th}$ shell is 13.

Q. Energy of an electron for hydrogen in $n^{th}$ orbit $E_n=-\frac{313.6}{n^2}$ kcal/mol. Find the value of 'n', if the energy of electrons in a certain orbit is - 19.6kcal/mol.

1. n = 4
2. n = 3
3. n = 2
4. n = 5

Q. The I.P. of a hydrogen like species is 36eV . What is the value of second excitation energy ? A)5 eV B)12eV C)32eV D)27e

Q. The amount of calcium oxide required to react completely with 852 g of P_4O_{10} is : ( Atomic mass of P = 31) ( CaO + P_4O_{10} → Ca_3(PO)_4 )

Q. 46.how many exchange pairs are possible in p5 configuration and how?

Q. H alpha line of balmer series is 6500A(amstrong).The wavelength of H gamma series i

Q. Ionisation energy of $H{e}^{+}$ is $8.71\times {10}^{-18}Jato{m}^{-1}$. The energy of the first stationary state (n = 1) of $L{i}^{2+}$ is:

1. $-4.41\times {10}^{-16}Jato{m}^{-1}$
2. $-1.96\times {10}^{-17}Jato{m}^{-1}$
3. $-2.76\times {10}^{-15}Jato{m}^{-1}$
4. $6.72\times {10}^{-17}Jato{m}^{-1}$

Q. The ionisation energy of hydrogen atom is 13.6 eV. What will be the ionisation energy of $L{i}^{2+}$ ion?

Q. Calculate the number of mole present in 200 amu of caco3 Calculate the number of hydrogen atoms present in 25.6g of sucrose has molar mass of 342.3g

Q. 50. A glass tube containing some excited H atom was allowed to relax to grind state and the emitted light was thrown on another glass tube containing some excited He+ ion where the electron in He+ ion was excited further higher level. At the end all the excited He+ ion was allowed to relaxed to ground state and the most energetic photon was found to have energy = 52.88 eV . Determine the orbit no. in which electron was present initially in H atom and He+ ion .

Q.

For ${\mathrm{He}}^{+}$the electron is in orbit with energy equal to $3.4\mathrm{eV}$. The azimuthal quantum number for that orbit is $2$ and the magnetic quantum number is $0$. Then which of the following is/are correct?

1. The subshell is $4\mathrm{d}$.

2. The number of angular nodes in it is $2$.

3. The numbers of radial nodes in it is $3$

4. The nuclear charge experienced in $\mathrm{n}=4$ is $2\mathrm{e}$ less than that in $\mathrm{n}=1$, where $\mathrm{e}$ is the electric charge.

Q. what is the meaning of Anti Penultimate shells?