Electron Configuration, Periodic Properties, and Trends Chapter 5

1. ATOMIC RADIUS

Atomic Radius (Covalent Radius) Defined as ______ the distance between the nuclei of identical atoms that are bonded together Ex. Cl 2 Cl ½ distance half

Atomic Radius Trend Largest : ____________ Smallest : __________ Increases down and to the left Francium Helium

Atomic Radius Trend REASON: increasing __________ charge (protons) – pulls the electrons _________ to the nucleus. Example: Which element has a larger atomic radius – Silicon or Sulfur? __________ Example: Which element has a larger atomic radius – Sodium or Potassium? _____________ Potassium nuclear Silicon closer

2. IONIZATION ENERGY

IONIZATION ENERGY Ion : an atom or group of bonded atoms that have a __________ or __________ charge. Ex. positivenegative Na + 11 protons = electrons = Cl - 17 protons = electrons =

IONIZATION ENERGY Ionization Energy : the energy required to remove ____ ________ from a neutral atom. Trend: oneelectron Increases up and to the right

Ionization Energy Lowest ionization energy : _____________ Group : _____________ Highest ionization energy: _____________ Group : _____________ Ex. What has the higher ionization energy – Aluminum or Phosphorus? _____________ Ex. What has the lower ionization energy – Calcium or Strontium? _____________ Francium Alkali Metals Helium Noble Gas Phosphorus Strontium

3. Electronegativity

Electronegativity Definition: the measure of the ability of an atom in a chemical compound to _______ electrons closer to it. _______ _______ don’t form compounds, so they are not included. attract Noble Gases

Electronegativity Periodic Trend Trend : Increases up and to the right

Electronegativity Highest Electronegativity : ________ Lowest Electronegativity : ________ Only element with 4.0 : __________ Only elements in the 3’s : _________, _________, __________. Fluorine Francium Fluorine OxygenChlorineNitrogen

4. Metallic Character

Metallic Character Largest : ____________ Smallest : __________ Increases down and to the left Francium Helium

5. IONIC RADII (Metal vs. Non- metal Trend)

Ionic Radii Positive ion : ________ ex. ______ Negative ion : _______ ex. ______ Neutral atoms _____ an electron to become __________ ions. Ex. K (19 electrons) K + (18 electrons) + 1e - Neutral atoms _____ an electron to become __________ ions. Ex. Cl (17 electrons) + 1e - Cl - (18 electrons) cation anion Na + lose Cl - positive gain negative

Ionic Radii Positive ions, ex. ___, are ________ than a neutral atom of that same element. (LOSE an electron) Negative ions, ex. ____, are _______ than a neutral atom of the same element. (GAIN an electron) Na + largerCl - smaller

REVIEW

Atomic Radius

Ionization Energy

Electronegativity

Metallic Character

Ionic Radii MetalsNon-metals Lose electrons to become ions Gain electrons to become ions Ion is smaller than atom Ion is bigger than atom Ex. Na > Na + Ex. Cl < Cl -