Paschen series of hydrogen atom comes under ___________ region.

When the electron jumps from any of the outer orbits to the first orbit, spectral lines are emitted in the ________ region.

Bohr's radius gives the radius of the _________ orbit.

The orbits in which electrons supposed to be revolving according to Rutherford are ___________

In Millikan's experiment an oil drop of mass 4.9 x 10^-14 kg is balanced by applying potential difference of 2 kV between the two plates which are 2 mm apart. The charge of the drop is ________________

The direction of deflection shows that cathode rays are _________ in charge

Arrange the spectral lines H_α, H_β, H_γ, H_δ in the increasing order of their wavelength.

The wave number of a spectral line of the hydrogen atom is equal to Rydberg's constant. The line is ______________.

In Millikan's experiment, the plates are kept at a distance of 16mm and are maintained at a potential difference of 10,000 V. The electric intensity is ______________.

When an electric field is applied to an atom each of the spectral lines split into several lines. This effect is known as ________________.

In a discharge tube, the source of positive rays is ________________.

J.J. Thomson's experiment demonstrated that ______________.

The minimum wavelength of the X-rays produced by electrons accelerated through a potential difference of V volts is directly proportional to _____________.

The total energy of electrons in the ground state of a hydrogen atom is -13.6 eV. The k.E of an electron in the first excited state is ____________.

In terms of Bohr radius a₀, the radius of the third Bohr orbit of a hydrogen atom is given by ______________.

The circumference of an electron's orbit of radius r must be an integral multiple of de Broglie wavelength that is ________________.

The half-life period of a radioactive element A is same as the mean life time of another radioactive element B. Initially both have the same number of atoms. Then _____.

The nucleus is approximately spherical in shape. Then the surface area of nucleus having mass number A varies as _____.

The electric potential of an electron is given by \(V={ V }_{ 0 } \ In\left( \frac { r }{ { r }_{ 0 } } \right) \), where r₀ is a constant. If Bohr atom model is valid, then variation of radius of n^th orbit r_n with the principal quantum number n is _____.

In a hydrogen atom, the electron revolving in the fourth orbit, has angular momentum equal to _____.