Chapter 7 Memory Bank

atomic-radius trend

increases down and left; largest toward the bottom-left

first-ionization-energy trend

increases up and right

electron-affinity trend

generally becomes more favorable toward the upper-right; halogens are especially favorable

cation (+)

an atom that lost electrons; usually smaller than the neutral atom

anion (-)

an atom that gained electrons; usually larger than the neutral atom

same element ion-size rule

more positive charge means a smaller ion

isoelectronic-species radius rule

same number of electrons; more protons means a smaller radius

same main-group valence pattern

same group and similar chemical properties

main-group valence electrons

Groups 1, 2, 13, 14, 15, 16, 17, 18 -> 1, 2, 3, 4, 5, 6, 7, 8 valence electrons

common ion charges

Group 1: +1; Group 2: +2; Group 15: -3; Group 16: -2; Group 17: -1

transition-metal cation electron removal

remove electrons from the highest n first; 4s electrons are removed before 3d

neutral-atom electron count

electrons = atomic number

positive charge electron count

subtract electrons

negative charge electron count

add electrons

isoelectronic

same electron count