$CrO_3$ is a/an ...

Assertion : Coloured cations can be identified by borax bead test.
Reason : Transparent bead $(NaBO_2 + B_2O_3)$ forms coloured bead with coloured cation.

The blue borax bead is obtained by which of the following?

The solution of $MnO_4^-$ is purple-coloured due to:

Highest fluoride and highest oxide of $Mn$ are respectively

Which of the following alloys is used in the construction of the outer fuselage of ultra-high-speed aircraft?