Atoms Test - 43...

A singly ionized helium atom in an excited state $$\left( n=4 \right)$$ emits a photon of energy $$2.6 eV$$. Given that the ground state energy of hydrogen atom is $$-13.6 eV$$, the energy $$\left( { E }_{ f } \right) $$ and quantum number $$\left( n \right) $$ of the resulting state are respectively,

The ionization energy of $${ Li }^{ 2+ }$$ is equal to

An electron in hydrogen atom after absorbing an energy photon jumps from energy state $${n}_{1}$$ to $${n}_{2}$$. Then it returns to ground state after emitting six different wavelengths in emission spectrum. The energy of emitted photons is either equal to less than the absorbed photons. The $${n}_{1}$$ and $${n}_{2}$$ are

The transition from from the state $$n = 5$$ to $$n = 1$$ in a hydrogen atom results in $$UV$$ radiation. Infrared radiation will be obtained in the transition.

Light of wavelength $$ \lambda = 4000 A^o $$ and intensity $$ 100 W/m^2 $$ is incident on a plate the threshold frequency $$ 5.5 \times 10^{14} Hz. $$ Find the number of photons incident $$ m^2 $$ per sec.

A gas of monoatomic hydrogen is bombarded with a stream of electrons that have been accelerated from rest through a potential difference of $$12.75V$$. In the emission spectrum one cannot observe any line of

The difference between a photon and neutrino is :

In Bohr's theory of Hydrogen atom, the electron jumps from higher orbit 'n' to lower orbit 'p'. The wavelength will be minimum for the transition

Electrons are excited form $$n=1$$ to $$n=4$$ state. During downward transitions, possible number of spectral lines observed in Balmer series is.

An electron enters a parallel plate capacitor with horizontal speed $$\mu$$ and is found to deflect by angle $$\theta$$ on leaving the capacitor as shown. It is found that $$\tan\theta=0.4$$ and gravity is negligible. If the initial horizontal speed is doubled, then $$\tan$$ will be.