The number of electrons present in all the completely filled subshells having $$\mathrm{n}=4$$ and $$\mathrm{s}=+\frac{1}{2}$$ is _______.

(Where $$\mathrm{n}=$$ principal quantum number and $$\mathrm{s}=$$ spin quantum number)

The orbital angular momentum of an electron in $$3 \mathrm{~s}$$ orbital is $$\frac{x h}{2 \pi}$$. The value of $$x$$ is ____________ (nearest integer)

Values of work function (W$$_0$$) for a few metals are given below

The number of metals which will show photoelectric effect when light of wavelength $$400 \mathrm{~nm}$$ falls on it is ___________

Given: $$\mathrm{h}=6.6 \times 10^{-34} \mathrm{~J} \mathrm{~s}$$

$$c=3 \times 10^{8} \mathrm{~ms}^{-1}$$

$$e=1.6 \times 10^{-19} \mathrm{C}$$