Which metal gives a blue borax bead?

Cigarette or gas lighter is made up of

The fusion of manganese dioxide with $KOH$ in the presence of an oxidizing agent like $KNO_3$ yields a compound. Identify the compound and its color.

Which from the following is the general formula of the compound obtained when lanthanoid $(Ln)$ reacts with carbon at elevated temperature?

Describe the preparation of potassium permanganate. State its physical properties,structure,and uses. Discuss its chemical properties and provide chemical reactions demonstrating the oxidizing character of $KMnO_{4}$.

Identify the correct $(T)$ and incorrect $(F)$ statements from the following:
$(a)$ $MnO_4^{2-}$ is diamagnetic.
$(b)$ $MnO_4^-$ is green and $MnO_4^{2-}$ is purple.
$(c)$ $K_2Cr_2O_7$ is yellow.
$(d)$ $K_2Cr_2O_7$ is orange.