The transition metal which forms a green compound in $+3$ oxidation state and a yellow-orange compound in $+6$ oxidation state is

Cigarette or gas lighter is made up of

Ferrosilicon is used in the steel industry as:

If an oxide of manganese has a value of magnetic moment $( \mu )$ of $4.9 \ BM$,then which oxide would it be?

Which of the following statements is true for $Fe_3O_4$?

The first transition series metal $M$ has the highest enthalpy of atomisation in its series. One of its aquated ion $(M^{n+})$ exists in green colour. The nature of the oxide formed by the above $M^{n+}$ ion is $:$