The chemical formula of 'tear gas' is

$\frac{\tan 80^{\circ}-\tan 10^{\circ}}{\tan 70^{\circ}}$ is equal to

The structure of $Cl_2O_7$ is ......

$A$ curve satisfying the initial condition,$y(1) = 0,$ satisfies the differential equation,$x \frac{dy}{dx} = y - x^2.$ The area bounded by the curve and the $x$-axis is

The number of $p\pi-d\pi$ 'pi' bonds present in $XeO_3$ and $XeO_4$ molecules,respectively,are:

Two particles $A$ and $B$,initially at rest,move towards each other under a mutual force of attraction. At an instance when the speed of $A$ is $v$ and the speed of $B$ is $2v$,the speed of the centre of mass $(CM)$ is: