Atomic Radius (CovalentRadius)• Defined as ______ the distance half between the nuclei of identical atoms that are bonded together• Ex. Cl2 Cl Cl ½ distance
Atomic Radius Trend Increases down and to the left Francium• Largest : ____________ Helium• Smallest : __________
Atomic Radius Trend• REASON: increasing __________ nuclear charge (protons) – pulls the electrons _________ to the nucleus. closer• Example: Which element has a larger atomic radius – Silicon or Silicon Sulfur? __________• Example: Which element has a larger atomic radius – Sodium or Potassium? _____________ Potassium
IONIZATION ENERGY • Ion : an atom or group of bonded atoms that have a __________ or __________ negative positive charge. Ex.Na+ Cl-11 protons = 11 + 17 protons = 17 +10 electrons = 10 - 18 electrons = 18 - 1+ 1-
IONIZATION ENERGY• Ionization Energy : the energy required to remove ____ ________ from a neutral one electron atom.• Trend: Increases up and to the right
Ionization Energy• Lowest ionization energy : _____________ Francium Group : _____________ Alkali Metals• Highest ionization energy: _____________ Helium Group : _____________ Noble GasEx. What has the higher ionization energy – Aluminum or Phosphorus? _____________ PhosphorusEx. What has the lower ionization energy – Calcium or Strontium? _____________ Strontium
Electronegativity• Definition: the measure of the ability of an atom in a chemical compound to _______ electrons closer to it. attract• _______ _______ don’t form Noble Gases compounds, so they are not included.
Electronegativity Periodic Trend• Trend : Increases up and to the right
Electronegativity• Highest Electronegativity : ________ Fluorine• Lowest Electronegativity : ________ Francium• Only element with 4.0 : __________ Fluorine• Only elements in the 3’s : Oxygen Chlorine Nitrogen _________, _________, __________.
Ionic Radii• Positive ion : ________ cation Na+ ex. ______• Negative ion : _______ anion ex. ______ Cl- lose• Neutral atoms _____ an electron to become positive __________ ions. Ex. K (19 electrons) K+ (18 electrons) + 1e- gain• Neutral atoms _____ an electron to become negative __________ ions. Ex. Cl (17 electrons) + 1e- Cl- (18 electrons)
Ionic Radii• Positive ions, ex. ___, are ________ Na+ smaller than a neutral atom of that same element. (LOSE an electron)• Negative ions, ex. ____, are _______ Cl- larger than a neutral atom of the same element. (GAIN an electron)