Why does Mn(II) show maximum paramagnetic character among the bivalent ions of the first transition series?

How do the ionic character and acidic nature vary among the oxides of first transition series?

Explain the magnetic properties of first transition series metal ions.

Amongest the bivalent ions of 3d-elements, Mn(II) shows maximum paramagnetic character, Substantiate.

Valence bond theory successfully explains the magnetic behaviour of complexes. The substances which contains unpaired electrons are paramagnetic and paramagnetic character increases as the number of unpaired electrons increases. Magnetic moment of a complex can be determined experimentally and by using formula sqrt(n(n+2)) and we can determine the number of unpaired electrons in it. This information is important in writing electronic structure of complex which in turn also useful in deciding the geometry of complex. The magnetic moment of complexes given below are in the order : {:(Ni(CO)_(4),[Mn(CN)_(6)]),("(I)","(II)"),([Cr(NH_(3))_(6)]^(3+),[CoF_(6)]^(3+)),("(I)","(II)"):}

The only electron in the hydrogen atom resides under ordinary conditions on the first orbit. When energy is supplied, the electron moves to higher energy orbit depending on the amount of energy absorbed. When this electron returns to any of the lower orbits, it emits energy. Lyman series is formed when the electron returns to the lowest orbit while Balmer series is formed when the electron returns to second orbit. Similarly, Paschen, Brackett and Pfund series are formed when electron returns to the third, fourth orbits from higher energy orbits respectively (as shown in figure) Maximum number of lines produced when an electron jumps from nth level to ground level is equal to (n(n-1))/(2) . For example, in the case of n = 4, number of lines produced is 6. (4 rarr 3, 4 rarr 2, 4 rarr 1, 3 rarr 2, 3 rarr 1, 2 rarr 1) . When an electron returns from n_(2) to n_(1) state, the number of lines in the spectrum will be equal to ((n_(2) - n_(1))(n_(2)-n_(1) +1))/(2) If the electron comes back from energy level having energy E_(2) to energy level having energy E_(2) then the difference may be expressed in terms of energy of photon as E_(2) - E_(1) = Delta E, lambda = (h c)/(Delta E) . Since h and c are constant, Delta E corresponds to definite energy, thus each transition from one energy level to another will prouce a higher of definite wavelength. THis is actually observed as a line in the spectrum of hydrogen atom. Wave number of the line is given by the formula bar(v) = RZ^(2)((1)/(n_(1)^(2)) - (1)/(n_(2)^(2))) Where R is a Rydberg constant (R = 1.1 xx 10^(7)) (i) First line of a series : it is called .line of logest wavelength. or .line of shortest energy.. (ii) Series limit of last of a series : It is the line of shortest wavelength or line of highest energy. The wave number of electromagnetic radiation emitted during the transition of electron in between two levels of Li^(2+) ion whose principal quantum numbers sum if 4 and difference is 2 is

Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following points: (i) electronic configurations (ii) oxidation states (iii) ionisation enthalpies and (iv) atomic sizes.

(a) A current-carrying circular loop lies on a smooth horizontal plane. Can a uniform magnetic field be set up in such a manner that the loop turns around itself (i.e., turns about the vertical axis). (b) A current-carrying circular loop is located in a uniform external magnetic field. If the loop is free to turn, what is its orientation of stable equilibrium? Show that in this orientation, the flux of the total field (external field + field produced by the loop) is maximum. (c) A loop of irregular shape carrying current is located in an external magnetic field. If the wire is flexible, why does it change to a circular shape?

Identify the correct statements among the following I) The transition elements have partially filled (n-l) d orbitals. II) Cu is a better conductor of electricity than that of Ag. III) Sc^(+3), zn^(+2) are diamagnetic whereas Ti^(+4) is paramagnetic. IV) Transitional elemelilts are less electro-positive than alkalimetals