Why Zn, Cd and Hg are not regarded as transtition elements?

Which of the d - block elements are not regarded as transition element ?

What are the characterstics of the transition elements and why are they called transition elements ? Which of the d-block elements may not be regarded as the transition elements ?

Why is 'Zn' not considered as transition element ?

Scandium forms no coloured ions, yet it is regarded as a transition elements. Why ?

Why are most of the ions transition elements coloured?

(i) Write the balanced equations to represent what happens when (a) acidified potassium permanganates reacts with hydrogen sulphide ? (b) acidified potassium dichromate solution reacts with iron (II) solution (ionic equation) ? (ii) The figure given below illustrates the first ionisation enthalpies of first, second and third series of transition elements. (a) Which series amongst the first, second and third series of transition elements have the highest first ionisation enthalpy and Why ? (b) Why there is a fall in IE_(2) from Cr to Mn and from Cu to Zn ? Explain.

The second and third rows of transition elements resemble each other much more than they resemble the first row. Why ?

Account of the following. (i) The enthalpy of atomisation is lowest for Zn in 3d -series of the transition elements. (ii) Identify the metal in MO_(3)F and justify your answer. (iii) Transition metals form a large number of complexes. (iv) d^(1) configuration is very unstable in ions.

Why are the salts of Zn , Cd and Hg are colourless.