Which aspect is similar in both chemical and nuclear reactions? a. both involve nuclear fusion. b. both involve nuclear fission. c. both may release heat and light. d. both involve the exchange of electrons.

The answer is C that is both nuclear and chemical reactions involve release of heat and light.

Chemical reactions usually involves rearrangements of electrons. While nuclear reactions involve change in atom's nuclei. Nuclear reactions involve reactions like nuclear fission and fusion. But both chemical as well as nuclear reactions involve release of heat and light.

"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."