Formation of a coloured solution is possible when the metal ion in the compound contains:

In which of the following pairs,the outermost electronic configuration will be the same?

Explain briefly how the $+2$ oxidation state becomes more stable in the first half of the first-row transition elements as the atomic number increases.

Given below are two statements :
Statement $I$ : The higher oxidation states are more stable down the group among transition elements unlike $p-$block elements.
Statement $II$ : Copper can not liberate hydrogen from weak acids.
In the light of the above statements,choose the correct answer from the options given below :

Which of the following represents the correct order of atomic radii (metallic radii) for the given transition elements?

Which of the following statements is incorrect?