# Bohr's Model of a Hydrogen Atom

## Trending Questions

**Q.**

Calculate the weight of CO having the same number of oxygen atoms as are present in 22g of CO2

**Q.**

What is the number of moles of Oxygen atom in 126 amu of HNO3

**Q.**

Two oxides of metal contain 50% and 40% of metal M respectively, if the formula of the first oxide is MO_{â€‹â€‹â€‹â€‹â€‹2}, the formula of the second oxide is?

**Q.**

What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4 to n = 2 of He+ spectrum?

**Q.**In which of the following transition will the wavelength be minimum:

- n =4 to n =2
- n =3 to n =1
- n =6 to n =4
- n =2 to n =1

**Q.**If the radius of 2nd Bohr orbit of hydrogen atom is r2, then the radius of the third Bohr orbit will be:

- 49r2
- 4r2
- 94r2
- 9r2

**Q.**The ionisation energy of hydrogen atom is 13.6 eV. What will be the ionisation energy of Li2+ ion?

**Q.**

What are the frequency and wavelength of a photon emitted during a transition from n = 5 state to the n = 2 state in the hydrogen atom ?

- 4.35Ã—1016 Hz, 691 nm
- 6.91Ã—1014 Hz, 434 nm
- 4.35Ã—1015 Hz, 450 nm
- 6.91Ã—1013 Hz, 400 nm

**Q.**

Calculate the mass of Na_{2}CO_{3} which will have the same number of molecules as contained in 12.3 gram of MgSO_{4}MgSO4.7H_{2}O

**Q.**The radius of which of the following orbits is the same as that of the first Bohr's orbit of hydrogen atom?

- Li2+ (n=2)
- He+ (n=2)
- Li2+ (n=3)
- Be3+ (n=2)

**Q.**What is the ratio of time periods in the second orbit of the hydrogen atom (TH) to the fourth orbit of He+ ion (THe)?

- 1:2
- 2:1
- 1:4
- 4:1

**Q.**

The energy associated with the first orbit in the hydrogen atom is –2.18 × 10–18 J atom–1 . What is the energy associated with the fifth orbit?

Calculate the radius of Bohr’s fifth orbit for hydrogen atom.

**Q.**The energy of second Bohr orbit of the hydrogen atom is −328 kJ mol−1; hence the energy of fourth Bohr orbit would be

- −41 kJ mol−1
- −1312 kJ mol−1
- −164 kJ mol−1
- −82 kJ mol−1

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

- 138
- 139
- 137
- 140

**Q.**

In an organic compound of molar mass 108 gram/mole C, H, and N atoms are present in 9:1:3.5 by weight find out the molecular formula of the compound

**Q.**If the ionisation energy for H atom is 13.6 eV, calculate the required energy in eV to excite it from the ground state to the first excited state.

- 13.6 eV
- 3.4 eV
- 10.2 eV
- 12.75 eV

**Q.**The ratio of the radii of the 2nd Bohr orbit of hydrogen atom to 3rd Bohr orbits of Li2+ is:

- 3:2
- 2:3
- 4:3
- 3:4

**Q.**

From a sample of 196g of H2SO4 if all the oxygen and hydrogen atoms are removed and converted to H2O. Find the max. mole of H2O formed.

**Q.**

A compound contains c=34.6percent , H=3.85 percent, andO=61.55percent .Calculate the empirical formula

**Q.**The frequency of light emitted for the transition n=4 to n=2 of He+ is equal to the transition in H-atom corresponding to which of the following:

- n=3 to n=1
- n=2 to n=1
- n=3 to n=2
- n=4 to n=3

**Q.**Calculate the energy of the photon emitted during the transition from energy levels n = 4 to n = 2 in a hydrogen atom.

- 4.09×10−19 J
- 2.42×10−19 J
- 5.42×10−19 J
- 3.42×10−19 J

**Q.**Which hydrogen like species will have the same radius as that of Bohr's first orbit of hydrogen atom?

- n=3, Li2+
- n=2, He+
- n=2, Be3+
- n=2, Li3+

**Q.**How many times does the electron go around the first orbit of hydrogen atom in one second?

- 13.18×1015
- 6.59×1013
- 2.07×1013
- 6.59×1015

**Q.**

Two elements${\mathrm{XY}}_{2}$ X atomic weight 75 and Y atomic weight 16 combine to give compound having 75.8% of X. The formula of the compound is

**Q.**According to Bohr's theory, the energy of an electron in the nth energy level of hydrogen like species is given by:

En=−21.76×10−19n2(Z2) J

Calculate the longest wavelength of light that will be needed to completely remove an electron from the third Bohr orbit of He+ ion.

- 2055 ∘A
- 205.5 ∘A
- 2.055 ∘A
- 20.55 ∘A

**Q.**Energy of an electron is given by

E=−2.178×10−18J(Z2n2) wavelength of light required to excite an electron in an hydrogen atom from level n = 1 to n = 2 will be

(h=6.62×10−34 J s and c=3.0×108m s−1)

- 6.500×10−7m
- 1.214×10−7m
- 8.500×10−7m
- 2.816×10−7m

**Q.**The energy of second Bohr orbit of the hydrogen atom is −328 kJ mol−1; hence the energy of fourth Bohr orbit would be

- −41 kJ mol−1
- −1312 kJ mol−1
- −164 kJ mol−1
- −82 kJ mol−1

**Q.**

A compound has the molecular formula X4O6 . If 11 g of X4O6 has 6.2 g of X, then what is the atomic mass of X?

**Q.**Find the number of waves made by a Bohr electron in one complete revolution in the 3rd orbit.

**Q.**Find the ratio of the difference in energy between the first and the second Bohr's orbit to that between the second and third Bohr's orbit of a hydrogen atom.

- 13
- 49
- 12
- 275