4.(a) Find the speed and the kinetic energy of a neutron having a de broglie wavelength of 0. 1 nm, typical of atomic spacing in crystals. (b) Label as true or false these statements involving the quantum numbers n, l, my. If a statement is false, write the correct one (1)The values of m that are allowed depend only on l and not on n(2) The n=4 shell contains four subshells. 3) The smallest value of n that can go with a i gIven Z is 1+1.(4)All states with H0 also have mo, regardless of the value of n (5) Every shell contains n subshells.(6)One of these subshells cannot exist: n=2, 1-1 n4, 1-3; n=3, 1-2; n=l, l-l.(c)For a hydrogen atom with F-l, the measured value of L, is 0. Find the possible values Lx can have.(6%+2%x6+2%) 5. Consider a grating with N slits, where the slit width a is assumed to be much smaller than the light wavelength. (a)Derive the intensity expression for the diffracted lights on the screen that is assumed far way from the grating. (b)Find the positions of the principal maxima of the diffraction pattern. (15%+5%)