12. Atoms

The ionisation energy of deuterium atom is (ionisation energy of H-atom is 13.6eV) are

• 13.6 eV

• slightly less than 13.6 eV

• slightly more than 13.6 eV

• 27.2 eV

if hydrogen atom and He⁺ ion have the same size , their respective states are

• 1,2

• 2,2

• 2,4

• not possible

The minimum energy to be supplied to a He⁺ ion in the ground state so that its size is larger than an H-atom in the

first excited state is

• 40.8 eV

• 48 eV

• 54.4 eV

• 27.2 eV

 The ratio of K.E. to the total energy of the electron in the hydrogen atom according to Bohr's theory is

• 1 : -1

• 1:1

• 1:2

• 1 : -2

The linear momentum of an electron in the nth orbit of hydrogen atom is proportional to

• n²

 The angular speed of the electrons in the nth Bohr orbit of the hydrogen atom is proportional to

• n

• n³

The radius of the hydrogen atom in its ground state is 5.3 × 10^-11m. After collision with an electron it is found to have

a radius of 21.2 x 10^-11m. The principal quantum number of the final state of the atom is

• 16

• 4

• 3

• 2

The concept of nuclear atom was established from the experiment of the

• emission of electrons from metal surfaces

• scattering of alpha particles by metal foils

• diffraction of electrons by crystals

• discharge of electricity through gas

 Find out which of the following is incorrect in Bohr model of the hydrogen atom

• The radius of the nth orbit is proportional to n

• The total energy of the electron in the nth orbit is inversely proportional to n.

• The magnitude of the potential energy of the electron in an orbit is greater than its kinetic energy.

• The speed of an electron is the nth orbit is inversely proportional to n.

The ionization potential of hydrogen is 13.6 V. The energy required to remove an electron from the second orbit of

hydrogen is

• 6.8 eV

• 3.4 eV

• 27.2 eV

• 1.7 eV