Hydrogen $(H)$, deuterium $(D)$, singly ionized helium $(H{e^ + })$ and doubly ionized lithium $(Li)$ all have one electron around the nucleus. Consider $n =2$ to $n = 1 $ transition. The wavelengths of emitted radiations are ${\lambda _1},\;{\lambda _2},\;{\lambda _3}$ and ${\lambda _4}$ respectively. Then approximately
${\lambda _1} = {\lambda _2} = 4{\lambda _3} = 9{\lambda _4}$
$4{\lambda _1} = 2{\lambda _2} = 2{\lambda _3} = {\lambda _4}$
${\lambda _1} = 2{\lambda _2} = 2\sqrt 2 {\lambda _3} = 3\sqrt 2 {\lambda _4}$
${\lambda _1} = {\lambda _2} = 2{\lambda _3} = 3\sqrt 2 {\lambda _4}$
A beam of fast moving alpha particles were directed towards a thin film of gold. The parts $A',\;B'$ and $C'$of the transmitted and reflected beams corresponding to the incident parts $A, B$ and $C$ of the beam, are shown in the adjoining diagram. The number of alpha particles in
An $\alpha$-particle of energy $4\ MeV$ is scattered through $180^o $ by a fixed uranium nucleus. The distance of the closest approach is of the order of
If radiation of allow wavelengths from ultraviolet to infrared is passed through hydrogen agas at room temperature, absorption lines will be observed in the :
State the limitations of plum pudding model of the atom.
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number $Z$ of hydrogen like ion is