Out of the following transition elements, the maximum number of oxidation states are shown by
(a) Sc(Z=21)
(b) Cr (Z=24)
(c) Mn (Z=25)
(d) Fe (Z=26)

In the following transition metals, the maximum number of oxidation states are exhibited by (a)chromium (Z=24) (b)manganese (Z=25) (c)Iron(Z=26) (d)titanium (Z=22)

The maximum oxidation state shown by V(Z=23),Cr(Z=24),Co(Z=27),Sc(Z=21) , are respectively

(a) Why do transition elements show variable oxidation states? (i) Name the element showing maximum number of oxidation states among the first series of transition metals from Sc (Z = 21) to Zn (Z = 30). (ii) Name the element which shows only + 3 oxidation state. (b) What is lanthanoid contraction? Name an important alloy which contains some of the lanthanoid metals.

Though a transition element, scandium (Z = 21) does not exhibit variable oxidation state.

The number of unpaired electron in Mn^(4+) (Z = 25) is :-

Arrange with explanation the following elements in the order of increasing ionisation energy. X(Z = 4) , Y(Z = 5), D(Z= 6), E(Z= 11)

Which of the followig ions will show highest magnetic moment (Z values for nautral atoms are as follows: N = 7, Cr = 24, Fe = 26 & Co = 27)

Give the decreasing order of E_((M^(3+))/(M^(2+))^(c-) Value for the following: (a). Co(Z=27) (b). Mn(Z=25) (c). Fe(Z=26) (d). Cr(Z=24)

For the four successive transition elements (Cr, Mn, Fe, and Co), the stability of +2 oxidation state will be there in which of the following order ? (At. Nos. Cr = 24, Mn = 25, Fe = 26, Co = 27)

The image of a complex number z in the imaginary axis is (A) z (B) iz (C) - z (D) -i z