Structure of atom

The Kinetic energy of the electron in an orbit of radius r in hydrogen atom from n= 10 state is

• e2 /r2
• e2/2r
• e2/r
• e2/2r2

The ionisation energy of 10 times ionised sodium atom is

• 13.6 eV
• 13.6x11 eV
• 13.6 /11 eV
• 13.6 x (11)2 eV

The radius of electron’s second stationary orbit in Bohr’s atom is R . The radius of the third orbit will be

• 3R
• 2.25 R
• 9 R
• R/3

In any Bohr orbit of the hydrogen atom, the ratio of kinetic energy to potential energy of the electron as

• ½
• 2
• -1/2
• -2

In Bohr model of the hydrogen atom, the lowest orbit corresponds to

• Infinite energy
• The maximum energy
• The minimum energy
• zero energy

A hydrogen atom (ionisation potential 13.6 eV) makes a transition from third excited state to first excited state. The energy of the photon emitted in the process is

• 1.89 eV
• 2.55 eV
• 12.09 eV
• 12.75 eV

If an electron jumps from 1st orbital to 3rd orbital, then it will

• Absorb energy
• Release energy
• No gain of energy
• None of these

The ratio of the frequencies of the long wavelength limits of Lyman and Balmer series of hydrogen spectrum is

• 27:5
• 5:27
• 4 :1
• 1:4

According to Bohr’s theory the moment of momentum of an electron revolving in second orbit of hydrogen atom will be

• 2π h
• π h
• h/ π
• 2h/ π

According to Bohr’s model , the radius of the second orbit of helium atom is

• 0.53 A
• 1.06 A
• 2.12 A
• 0.265 A