Transcript A: They are involved in bonding.

11.4
Electron
Configuration
Period: 1
Group: 2
Electron Configuration Diagram
• Electron Configuration: Electron
arrangement.
• Orbital/box diagram.
• Opposing arrows = Opposing electron
spins.
• All 2p orbitals have the same energy.
• There are 3 2p orbitals.
Electron Configuration Diagram
Cont.
• Q: How are opposite
electron spins shown
in box diagrams?
• A: They are shown
by opposing arrows
Classifying Electrons
• Valence electrons- electrons at highest
electron level [involved in bonding]
• Core electron- inner most electrons [ not
involved in bonding]
• Atoms of elements in the same group
have same # of electrons in a given type
orbital.
Classifying Electrons Cont.
• Q: Why are
valence electrons
important?
• A: They are involved in
bonding.
Wave-Mechanical Model and
Valence-Electron Configuration
• The model pictures electrons arranged in
orbitals.
• As the atoms build up the orbitals reoccur
in going from one principal energy to
another.
• Elements with a particular type of valence
configuration all show very similar
chemical behavior.
Wave-Mechanical Model and ValenceElectron Configuration Cont.
• Q: What do electrons
with a particular type of
valence configuration
show?
•A: Similar chemical behavior
and bonding behavior.
Valence Electron Model
Atomic Properties & Sizes
• Metals: lustrous appearance, malleable,
conducts heat & electricity.
• Non Metals: opposite of metals.
• Sizes: atoms get larger as we go down a
group and get smaller as we go from left to
right across a period on a periodic table.
Atomic Properties & Sizes
• Q: Describe metals.
•A: They are lustrous, malleable and
can conduct electricity very well.
More on Atomic Sizes
• Atoms get bigger as electrons are added
to larger principal energy levels.
• The atom gets smaller as the electron
cloud is drawn in by the increasing nuclear
charge.
Ionization Energies
• Ionization energy: The energy required to
remove an electron from an individual
atom in the gas phase.
• Metals have relatively low ionization
energies. Non-metals have relatively large
energies.
• [ More energy going up and right across a
periodic table, and less energy going down
and left across a p-table.]
Ionization Energy
Ionization Energy
• Q: Describe a metals
ionization energy.
•A: Metals have a relatively low
ionization energy compared to
that of a Non Metal.
Quiz
1. How can you represent electron
configuration?
2. What do elements in the same group have
in common?
3. How does wave mechanical model picture
electrons?
4. What are elements with metal and nonmetal properties?
5. What makes the atom smaller?
Quiz Answers
1.
2.
3.
4.
5.
By using the orbital/box diagram.
Number of valence electrons.
It pictures electrons arranged in orbital.
Metalloids or semi-metals
The atom gets smaller as the electron
cloud is drawn in by the increasing
nuclear charge.
Links & References
• http://facultyfp.salisbury.edu/dfrieck/htdocs
/212/rev/table/trends.htg/img2.gif
• https://teach.lanecc.edu/gaudias
scheme.gif
• http://web.buddyproject.org/wed017/web0
17/image/atom.JPG
• http://web.inc.bme.hu/csonka/csg/oktat/en
glish/ionization-energy-1.jpg
• World of Chemistry – McDougal Littell