The spectrum of $Li^{2+}$ is similar to that of:

Which one of the following is not the characteristic of Planck's quantum theory of radiation?

The energy of a photon is $3 \times 10^{-12} \ erg$. What is its wavelength in $nm$? $(h = 6.62 \times 10^{-27} \ erg \cdot s; \ c = 3 \times 10^{10} \ cm/s)$

The value of the work function of a metal $X$ is $3.1 \ eV$. What is its threshold frequency (in $Hz$)? (Given: $h = 6.62 \times 10^{-34} \ J \cdot s$)

In an orbital,the value of $K.E.$ is equal to:

Which one of the following statements is not correct?