Click the button that shows the correct relationship of the electron affinities of the elements bromine and chlorine. Chlorine’s
electron affinity value is more negative than the electron affinity value of bromine. Bromine’s electron affinity value is more negative than the electron affinity value of chlorine. This information cannot be determined using the periodic table.
Chlorine's electron affinity value is more negative than the electron affinity value of bromine.
The first electron affinity of an element measures the energy change when one mole of electrons are added to one mole of the atom under gaseous state. A negative electron affinity value indicates a release of energy whereas a positive value corresponds an input of energy.
Both chlorine and bromine are nonmetal elements near the right end of a modern periodic table and would release energy on the addition of the first electron to their neutral atoms. The exact quantity of energy released is dependent on the atom's attraction on an additional electron. Chlorine is found in the third period of the periodic table. Bromine is located one period underneath chlorine and would have one more occupied valence shell than chlorine does. Both elements have a effective nuclear charge of +7 as group seven elements, whereas with one less occupied layer of electrons, the separation between the center of the positive charge in a chlorine atom and the extra electron would be smaller than that in a bromine atom. Chlorine atoms thus pose a stronger attraction on electrons added and release more energy than bromine does. The first electron affinity value of chlorine is thus more negative than that of bromine.
