CHEM 1122 Lecture 7: Atoms and Elements
Document Summary
Insulators => nonconductive: metalloids (anion, what makes a metalloid, semiconductor, have mixed properties of metal and nonmetal. Alkali metals - group 1 = li, na, k. Alkali earth metals - group 2 = be, mg, ca. Transition metals - groups 3-12 = sc to zn and down. Halogens - group 17 = f, cl, br, i. Noble gases - group 18 = ne, ar, kr: forming ions, ion = charged atom. Positive charge = cation: negative charge = anion, ex) na (cid:314) 1s22s22p63s1 (cid:314) 11 protons, 11 electrons. Na+ (cid:314) 1s22s22p6 (cid:314) 11 protons, 10 electrons: ex) ca (cid:314) 1s22s22p63s23p64s2 (cid:314) 20 protons, 20 electrons. Ca2+ (cid:314) 1s22s22p63s23p6 (cid:314) 20 protons, 18 electrons: ions want to have a noble gas configuration, easier to write core electron as noble gas configuration, only account for valence ex) ca = [ar] 4s2. F = [he] 2s22p5 f- = [he] 2s22p6 or [ne]
