question

given reasons for the following:

(i) the transition metals generally form coloured compounds.

(ii)  value for  is highly positive than that for  couple.

(iii) the chemistry of actinoids elements is not so smooth as that of the lanthanoids.

 

 

 

 

 

 

 

 

(i) colour is due to the presence of incomplete d- subshell. during these transtions, they emit raditions corresponding to some wavelength in the visible region spectrum.

(ii) it is so because the third ionisation energy of mn is very high

(iii) this is due to the much smaller energy difference between 5f,6d and 7s subshells of actinoids than 4f, 5d and 6s subshells of lanthanoids.