Which of the following statements(s) is // are correctly applicable to all the transition elements with atomic number 21-29 ? 1. Thelowest oxidation states is +1. 2.The 4s orbital is completely filled in the group state. 3.The 3d orbital is incompletelyfilled in the group state. 4. The ion in the +2 oxidation state is paramagnetic.

Which of the following statements(s) is // are correctly applicable to

1.	Which of the following statements(s) is // are correctly applicable to all the transition elements with atomic number 21-29 ? 1. Thelowest oxidation states is +1. 2.The 4s orbital is completely filled in the group state. 3.The 3d orbital is incompletelyfilled in the group state. 4. The ion in the +2 oxidation state is paramagnetic.
Answer» 1,2 and 3 3 and 4 only 4 only 3only Solution :Lowest oxidation state is `+1` only in case of Cu. Hence, (1) is wrong. 4s orbital is not completely FILLED in Cu and Cr. Hence, (2) is wrong. 3d orbital is not incompletely filled in cae of Cu. Hence, (3) is wrong. Ions is `+2` oxidation state of all elements ( 21-29) hav unpaired electrons and, therefore, PARAMAGNETIC. Hence, ( 4) is CORRECT.