3. Atomic Radius (Covalent
Radius)
• Defined as ______ the distance
half
between the nuclei of identical atoms
that are bonded together
• Ex. Cl2
Cl Cl
½
distance
4. Atomic Radius Trend
Increases
down and
to the left
Francium
• Largest : ____________
Helium
• Smallest : __________
5. 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
7. 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-
8. IONIZATION ENERGY
• Ionization Energy : the energy required to
remove ____ ________ from a neutral
one electron
atom.
• Trend: Increases up and to the right
9. Ionization Energy
• Lowest ionization energy : _____________
Francium
Group : _____________
Alkali Metals
• Highest ionization energy: _____________
Helium
Group : _____________
Noble Gas
Ex. What has the higher ionization energy –
Aluminum or Phosphorus?
_____________
Phosphorus
Ex. What has the lower ionization energy –
Calcium or Strontium?
_____________
Strontium
11. 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.
13. Electronegativity
• Highest Electronegativity : ________
Fluorine
• Lowest Electronegativity : ________
Francium
• Only element with 4.0 : __________
Fluorine
• Only elements in the 3’s :
Oxygen Chlorine Nitrogen
_________, _________, __________.
17. 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)
18. 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)
