What is produced when $Mg$ burns in $CO_2$?

If $P=(0,1,0)$ and $Q=(0,0,1)$,then the length of the projection of the line segment $PQ$ on the plane $x+y+z=3$ is

Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids,the main reason being

The point $P$ is equidistant from $A(1, 3)$,$B(-3, 5)$,and $C(5, -1)$. Then $PA =$

During the depression in freezing point experiment,an equilibrium is established between the molecules of

An infinitely long rod lies along the axis of a concave mirror of focal length $f$. The near end of the rod is at a distance $u > f$ from the mirror. Its image will have a length