Short Answer Type
Long Answer TypeDiscuss the characteristics of group 13 elements in terms of:
(i) Atomic and ionic radii
(ii) ionisation enthalpy
(iii) Density, melting point and boiling points.
Short Answer TypeHow would you explain the lower atomic radius of Ga as compared to Al ?
It is due to the poor shielding of the valence electrons of Ga by the inner 3d-electrons. As a result, the effective nuclear charge of Ga is somewhat greater in magnitude than that of Al. Thus, the electrons in gallium experience the greater force of attraction by the nucleus than in aluminium. Hence the atomic size of Ga(135 pm) is slightly less than that of Al(143 pm).
Long Answer TypeExplain the following:
(i) Boron is trivalent
(ii) Boron and aluminium tend to form covalent compounds.
Discuss the pattern of variation in the oxidation states of B(Boron) to Tl(Thallium).
Or
What is inert pair effect? Illustrate it with reference to Boron family.
Short Answer TypeStandard electrode potential values 
and that of 
is +1.26 V. Predict about the formation of M3+ ion in solution and compare the electropositive character of the two metals.
Switch
