What are transition metals? Give four examples.

Explain the oxidation states of 4d series elements.

What are inner transition elements?

Justify the position of lanthanoids and actinoids in the periodic table.

What are actinides? Give three examples.

Why Gd³⁺ is colourless?

Explain why compounds of Cu²⁺ are coloured but those of Zn²+ are colourless.

Describe the preparation of potassium dichromate.

What is lanthanoid contraction and what are the effects of lanthanoid contraction?

Complete the following.
a. 3MnO₄^2- + 4H⁺ ⟶?
b. C₆H₅CH₃ \(\overset { acidified }{ \underset { KMnO_{ 4 } }{ \longrightarrow } } \)?
c. MnO₄^- + Fe²⁺ ⟶?
d. KMnO₄ \(\overset { \triangle }{ \underset { Red\ hot }{ \longrightarrow } } \) ?
e. Cr₂O₇^2- + 6I^- + 14H⁺ ⟶?
f. Na₂Cr₂O₇ + 2KCl ⟶?

Orange colour of Cr₂O₇^2- ion charges to yellow in alkali and yellow solution turns out orange on adding H⁺ ions. Explain why?

Many industrial processes use transition metal or their compounds as catalyst. Why?

What is an alloy? Give an example.

What are the conditions for alloy formation?

Write the equation for the action of heat on KMnO₄