Treatment of molecule a with mg forms a grignard reagent that reacts with ch2═o to form h after water is added to the reaction mixture. h has a molecular ion in its mass spectrum at m/z = 86, and shows fragments at 71 and 68. h exhibits absorptions in its ir spectrum at 3600−3200 and 1651 cm−1, and has the 1h nmr spectrum given below. draw the structure of h.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."

4d^55s^1 ( third choice)