The first line in the Lyman series has wavelength $\lambda $. The wavlength of the first line in Balmer series is
$\frac{2}{9}\lambda $
$\frac{9}{2}\lambda $
$\frac{5}{27}\lambda $
$\frac{27}{5}\lambda $
What was the thickness of the gold foil kept in the Geiger-Marsden scattering experiment?
An electron having de-Broglie wavelength $\lambda$ is incident on a target in a X-ray tube. Cut-off wavelength of emitted $X$-ray is :
How many energy rays of $\alpha -$ particles emitted from $_{83}^{214}Bi$ were taken?
The ratio of ionization energy of Bohr's hydrogen atom and Bohr's hydrogen like lithium atom is
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