1. Atomic Radius/Ionic Radius 2. Metallic Character 3. Ionization Energy 4. Electronegativity FOUR PERIODIC PROPERTIES:
What is it? The distance from the nucleus to the outer/valence energy level. ATOMIC Radius Small atomic radius Large atomic radius
The Trend for atomic radius Increases Increases
As you go from left to right the atomic radius gets smaller. BUT WHY? The nuclear charge (# of p+ inside the nucleus) increases. This increase in positive charge pulls the e- cloud closer to the nucleus; therefore decreasing the atomic radius! Why the trend within the period?
ANIONS: (- charge) become LARGER than the parent neutral atom. They are gaining electrons, the e- spread out a little making the ion formed a little larger. [NONMETALS] CATIONS: (+ charge) become SMALLER than the parent neutral atom. They are losing electrons from the valence shell. [METALS] Ionic radius:
Ionic radii Anions: Get Larger Cations: Get Smaller
Metallic character Remember where metals and nonmetals are located on the periodic table. That makes this trend one of the easiest to remember!
What is that??? It is the energy required to remove the most loosely held electron from the valence shell of the atom in the gaseous phase. Abbreviated IE Ionization energy
Ie’s trend Within a PERIOD, the IE increases with atomic #. The larger the atomic #, the larger the positive charge in the nucleus which means a stronger hold on the e-s; more energy to remove it. Within a GROUP, the IE decreases as you go down the group. Electrons are further away from the nucleus AND the shielding effect.
What is it??? It is a measure of the ability of an atom to attract electrons to itself. Arbitrary scale - values range from 0.7 to 4.0 Fluorine has the highest electronegativity (4.0). Noble gases are excluded since they are already stable and don’t want to attract any electrons. electronegativity
Electronegativity trend FOXY Fluorine! FREAKY Francium
TRENDS SUMMARY INCREASES Atomic radius Metallic character INCREASES INCREASES Ionization Energy Electronegativity INCREASES