The oxidation state of $Xe$ in $XeO_3$ and the bond angle in it respectively are:

Methanogens belong to:

In the Bohr series of lines of the hydrogen spectrum,the third line from the red end corresponds to which one of the following inter-orbit transitions in an atom of hydrogen?

Energy required to remove an electron from an aluminium surface is $4.2 \text{ eV}$. If light of wavelength $2000 \text{ \AA}$ falls on the surface, the velocity of the fastest electron ejected from the surface will be:

$A$ particle moving with a uniform acceleration travels $24 \,m$ and $64 \,m$ in the first two consecutive intervals of $4 \,sec$ each. Its initial velocity is............$m/sec$.

$\frac{\sqrt{8+\sqrt{28}}+\sqrt{8-\sqrt{28}}}{\sqrt{8+\sqrt{28}}-\sqrt{8-\sqrt{28}}}$ is equal to