Why 3d-series of elements acts as good catalyst?

Why 3 d - series of elements acts as good catalyst?

Why does vanadium pentoxide act as a catalyst ?

In stratosphere , which of the following element acts as a catalyst in degradation of ozone an release of molecular oxygen ?

State reasons for the following: (i) Cu(I) ion is not stable in an aqueous solution. (ii) Unlike Cr^(3+)Mn^(2+), Fe^(3+) and the subsequent other M2+ ions of the 3d series of elements, the 4d and the 5d series metals generally do not form stable cationic species.

3d-series elements exhibit vaiable oxidation states. Why ?

3d-series elements exhibit variable oxidation states. Why ?

The thermonuclear reaction of hydrogen inside the stars is taking place by a cycle of operations. The particular element which acts as catalyst is

Which one of the following also acts as a catalyst in a bacterial cell ?