Physics Unit 10 Test

The transition from state n = 3 to n =1 in a hydrogen like atom results in ultra violet radiation. Infrared radiation will be obtained in transition from

Two radioactive elements X and Y have half-lives of 50 and 100 minutes respectively. Initial sample of both the elements have same no of atoms. The ratio of the remaining number of atoms of X and Y after 200 minutes is

• 2

• 1/4

• 4

• 5/4

• Electron

• Neutron

• Positron

With the increase in quantum number the energy difference between consecutive energy levels

• Remains constant

• Decreases

• Increases

• Sometimes increases sometimes decreases

The Balmer series for hydrogen atom corresponds to electronic transitions that terminate in the state of quantum number n = 2. The longest wavelength of photon emitted is

During the transition of Electron of Hydrogen atom from higher orbit to a third orbit, a photon of:

• Paschen series is emitted

• Lyman series is emitted

• Balmer series is emitted

• Brakett series is emitted

An electron jumps from the 4th orbit to the 2nd orbit of hydrogen atom. Given the

Rydberg's constant R = 10 ⁵ cm ^-1 . The frequency in Hz of the emitted radiation will be

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

Which two nuclei contain the same number of neutrons?