Total number of acidic oxides among

$$\mathrm{N_2O_3,NO_2,N_2O,Cl_2O_7,SO_2,CO,CaO,Na_2O}$$ and $$\mathrm{NO}$$ is ____________.

Assume that the radius of the first Bohr orbit of hydrogen atom is 0.6 $$\mathrm{\mathop A\limits^o }$$. The radius of the third Bohr orbit of He$$^+$$ is __________ picometer. (Nearest Integer)

For conversion of compound A $$\to$$ B, the rate constant of the reaction was found to be $$\mathrm{4.6\times10^{-5}~L~mol^{-1}~s^{-1}}$$. The order of the reaction is ____________.

Let $$y=y(x)$$ be the solution of the differential equation $$x{\log _e}x{{dy} \over {dx}} + y = {x^2}{\log _e}x,(x > 1)$$. If $$y(2) = 2$$, then $$y(e)$$ is equal to