If the internal energy of the products of a reaction is higher than the internal energy of the reactants, what is the sign of ΔE for the reaction? In which direction does energy flow?
Solution: Step1: a) According to Pauli’s exclusion principle, an orbital can accommodate maximum of two electrons and these must have opposite spins. In the above diagram, the two electrons in the first p orbital are having same spin which is not possible. Hence, the diagram is wrong. Step2: b) The correct diagram for the electron distribution is: Step3: c) The number of electrons in the outermost p orbital is 4, i.e., the outermost electronic configuration of the group is ns np . Out of all the groups, the family of ele me nts having ns np 4 outermost configuration, i.e., having 4 electrons in their outermost p orbital is oxygen family(g roup 16 elements). All the elements of group 16 has 4 electrons in their valence p orbital 2 4 having outermost electronic configuration ns np as shown below: --------------------