Identify the element for which +1 oxidation state is more stable than +3 oxidation state.

Identify the correct statements from the following.

(i) Ti (IV) is more stable than Ti (III) and Ti (II).

(ii) Among $3 d$-series elements (From $Z=22$ to 29). Only copper has positive reduction potential $\left(M^{2+} / M\right)$.

(iii) Both Sc and Zn exhibit +1 oxidation state.

The product formed during thermal decomposition of ammonium dichromate are

In +2 oxidation state, which of the following lanthanoids act as reducing agents?