The uncertainty in the position of electron $(\Delta x)$ is approximately 100 pm . The uncertainty in momentum (in $\mathrm{kg} \mathrm{ms}^{-1}$ ) of an electron $\left[h=6.626 \times 10^{-34} \mathrm{Js}\right]$

Which of the following statements are correct?

I. The energy of hydrogen atom in its ground state is -13.6 eV .

II. On the basis of Bohr's model, the radius of the 3rd orbit of hydrogen atom is 158.7 pm .

III. The order of radius of the first orbit of $\mathrm{H}, \mathrm{He}^{+}, \mathrm{Li}^{2+}$ and $\mathrm{Be}^{3+}$ is $\mathrm{H}>\mathrm{He}^{+}>\mathrm{Li}^{2+}>\mathrm{Be}^{3+}$.

When a metal surface is irradiated with light of frequency $x \mathrm{~Hz}$, the kinetic energy of emitted photoelectrons is $z \mathrm{~J}$. When the same metal is irradiated with light of frequency $y \mathrm{~Hz}$, the kinetic energy of emitted electrons is $z / 3 \mathrm{~J}$. What is threshold frequency (in Hz ) of metal?

Identify the correct statements from the following

I. Isotopes of an element show different chemical behaviour.

II. Lyman series of lines of hydrogen spectrum appear in UV region.

III. The oscillating electric and magnetic field components of electromagnetic radiation are perpendicular to each other and both are perpendicular to the direction of propagation of radiation.