When the excited electron of a H atom from n = 5 drops to the ground state, the maximum number of emission lines observed are _____________.

If the work function of a metal is 6.63 $$\times$$ 10^$$-$$19J, the maximum wavelength of the photon required to remove a photoelectron from the metal is ____________ nm. (Nearest integer)

[Given : h = 6.63 $$\times$$ 10^$$-$$34 J s, and c = 3 $$\times$$ 10⁸ m s^$$-$$1]

Consider the following set of quantum numbers.

The number of correct sets of quantum numbers is __________.

If the uncertainty in velocity and position of a minute particle in space are, 2.4 $$\times$$ 10^$$-$$26 (m s^$$-$$1) and 10^$$-$$7 (m) respectively. The mass of the particle in g is ____________. (Nearest integer)

(Given : h = 6.626 $$\times$$ 10^$$-$$34 Js)