Calculate the de Broglie wavelength of an electron in the first Bohr orbit of a hydrogen atom if the velocity of an electron in the first orbit is $2.2 \times 10^6 \text{ ms}^{-1}$. [mass of electron $= 9.1 \times 10^{-31}$ kg, plank's constant (h) $= 6.626 \times 10^{-34}$ J s]

Which group elements have the smallest atomic radii in their respective periods?

What happens to the size of atoms in p-block elements when we move from left to right in the same period?

Which of the following order of dipole moment for stated molecules is correct?