Periodic Trends Chemistry 2

Essential Question How do the properties of elements repeat in periodic manner by virtue of their organization on the periodic table?

Periodicity Repeating trends in: Atomic Radius Ionization energy (IE) Electronegativity

Atomic Radius Distance from the center of the nucleus to the edge of the electron cloud

Ionic Radii Cations Anions Smaller than their parent atom K vs. K+ Anions Larger than their parent atom O vs. O-2

Checkpoint List in order from smallest to largest atomic radii: Ti, Na, F, Cu,

Ti, Na, F, Cu,

Ionization Energy Energy required to remove an electron A + energy → A+ + e-

Ionization Energy Factors affecting: Valence electrons in the outer shell The closer to 8 electrons, the harder to remove The number of energy levels The closer to the nucleus the energy level is, the harder it is to remove.

Ionization Energy Trend: IE decreases down a group IE increases L to R across a period

Checkpoint #2 Place these elements in order from lowest to highest IE: Mn, Cs, Cl, F

Mn, Cs, Cl, F

Electronegativity The ability of an atom to attract electrons in a bond

Electronegativity Trend: Most Electronegative – Fluorine Increases up a group Increases L to R across a period Most Electronegative – Fluorine Least – Francium

Electronegativity

Checkpoint #3 Place in order from high to low electronegativity: N, Mg, Fe, F, Pt, Sr