CHEM 101 Lecture Notes - Lecture 6: Ionic Compound, Electron Affinity, Valence Electron
Document Summary
Halogens and nonmetals accept electrons to become anions. Ions of main groups (1a-7a) lose or gain electrons to achieve the electron configuration of a noble gas. 1: atoms (ions) with the same electron configuration are isoelectronic. Main group ions are isoelectronic to noble gases: aufbau principle: applies to the formation of ionic compounds, main groups: i. ii. iii. Electrons given up by a metal when forming a cation come from the highest energy occupied orbital (biggest one, most outside). Electrons accepted by nonmetals when forming an anion go into the lowest energy (innermost, closest to the nucleus). Noble gas configuration equals the closest noble gas to that element: transition metals: i. ii. Form with nonmetals to make cations: lose valence shell electron first (s) then losing the d orbital. Values are positive, energy always added to move electron. So they attain a noble gas configuration (with filled s and p shells). i. ii. iii. iv.
