2CA StandardsStudents know how to use the periodic table to identify trends in ionization energy, electronegativity, and the relative sizes of ions and atoms.
3Atomic RadiusDefinition: Half of the distance between nuclei in covalently bonded diatomic moleculeRadius decreases across a periodIncreased effective nuclear charge due to decreased shieldingRadius increases down a groupEach row on the periodic table adds a “shell” or energy level to the atom
6Ionization EnergyDefinition: the energy required to remove an electron from an atomTends to increase across a periodAs radius decreases across a period, the electron you are removing is closer to the nucleus and harder to removeTends to decrease down a groupOuter electrons are farther from the nucleus and easier to remove
8ElectronegativityDefinition: A measure of the ability of an atom in a chemical compound to attract electronsElectronegativity tends to increase across a periodAs radius decreases, electrons get closer to the bonding atom’s nucleusElectronegativity tends to decrease down a group or remain the sameAs radius increases, electrons are farther from the bonding atom’s nucleus
12Ionic Radii Cations Anions Positively charged ions formed when an atom of a metal loses one ormore electronsCationsSmaller than the correspondingatomNegatively charged ions formedwhen nonmetallic atoms gain oneor more electronsAnionsLarger than the correspondingatom