According to Bohr's theory, the angular momentum of an electron in 5^th orbit is

Uncertainty in the position of an electron (mass = 9.1 $$\times$$ 10^-31 kg) moving with a velocity 300 ms^-1, accurate upto 0.001% will be (h = 6.63 $$\times$$ 10^-34 Js)

Which of the following sets of ions represents a collection of isoelectronic species?

Following statements regarding the periodic trends of chemical reactivity of the alkali metals and the halogens are given. Which of these statements gives the correct picture?