The ionization energy of a singly ionized helium ion $(He^+)$ is equal to:

The difference in radii between the fourth and third Bohr orbits of $He^{+}$ (in $m$) is:

$A$ source of monochromatic radiation of wavelength $400 \, nm$ provides $1000 \, J$ of energy in $10 \, seconds$. When this radiation falls on the surface of sodium,$x \times 10^{20}$ electrons are ejected per second. Assume that wavelength $400 \, nm$ is sufficient for ejection of electrons from the surface of sodium metal. The value of $x$ is $......$. (Nearest integer) $(h = 6.626 \times 10^{-34} \, Js)$

Circumference of the first orbit of hydrogen atom is given by the formula :

The energy of an electron in the ground state $(n=1)$ for $He^{+}$ ion is $-x \ J$. What is the energy for an electron in the $n=2$ state for $Be^{3+}$ ion in $J$?

When an electron jumps from $n = 5$ to $n = 2$ with all possible transitions,which of the following statements is correct?