## Chemistry and Chemical Reactivity (9th Edition)

Na: Group 1, period 3 Al: Group 13, period 3 B: Group 13, period 2 C: Group 14, period 2 a) Na, atomic radius is bigger in later periods and earlier groups. b) C, the negative of the electron attachment energy is greater in later groups and earlier periods c) $Na\lt Al \lt B\lt C$, ionization energy is greater in later groups and earlier periods.