Periodic Trends Continued Atomic Radius Ionization Energy Ionic Size Electronegativity

Trend: Atomic Radius Atomic Radius is: ½ the distance between nuclei of 2 atoms of the same element. Trend Reasoning: Increased nuclear charge pulls e- closer More principal energy levels = Bigger atom

Atomic Radii for Selected Atoms

Trend: Ionization Energy Ions: are atoms that have gained or lost electrons. Ionization Energy is: The energy required to remove an electron from a neutral atom at ground state. Trend Reasoning: Increased nuclear charge pulls e- closer so they are harder to lose. As the atom gets bigger the nucleus has less effect on the e-in the highest shells.

Trend: Ionic Size Metals tend to lose electrons to nonmetals that tend to gain electrons. Cations are + ions (metals) Anions are – ions (nonmetals) Trend Reasoning: Increased nuclear charge pulls e- closer so they are harder to lose. More principal energy levels = Larger

Trend: Electronegativity Ability of an atom to attract electrons from other atoms (Electron Greediness) Trend *Excludes Noble gases Reasoning: Metals tend to lose e- Nonmetals tend to gain e- The atoms are bigger and the nucleus has little attraction for extra electrons.