CH 105 1E SI
Test_2_W1
Valence Electrons
1.
2.
3.
4.
5.
Valence electrons are electrons in the _outer shell_ of an atom.
Nitrogen has _five_ valence electrons.
Carbon has _four_ valence electrons.
Fluorine has _seven_ valence electrons.
What is the name of the group of elements that have 8 valence electrons?
Noble gases
The Octet Rules
1. What is the octet rule?
Rule stating that Atoms (or ions) which have 8 valence electrons are in a more stable
electron configuration
2. Ions are atoms or groups of atoms which have gained or lost _(valence) electrons_.
3. How do we designate the charge of an ion?
By a number and sign (+/-) to the upper right of the chemical symbol (Ex. Cr3+)
4. Calcium (gains/loses) _two_ electrons to become an ion.
5. Nitrogen (gains/loses) _three_ electrons to become an ion.
6. Oxygen (gains/loses) _two_ electrons to become an ion.
7. _Anions_ are ions with a negative charge.
8. _Cations_ are ions with a positive charge.
9. What do two particles that are isoelectronic have in common?
Electron Configuration
Isoelectronic Ions and Atoms
1. Name three ions that are isoelectronic with Neon.
F-, O2-, N3-, Na+, Mg2+
2. Name three ions that are isoelectronic with Argon.
P3-, S2-, Cl-, K+, Ca2+
Ionization Energy
1. What exactly is ionization energy?
The energy required to remove an electron from the valence shell of an atom
2. What trend do you recognize about ionization energy?
Increases across a period and increases going up a group
CH 105 1E SI
Test_2_W1
3. Which would have higher ionization energy, Ne or P?
Ne, because it is further left and higher up on the periodic table
4. Which would have higher ionization energy, N or Mg?
N, because it is further left and higher up on the periodic table
Ion Nomenclature
1. Calcium as an ion would be called a _Calcium ion_.
2. Chlorine as an ion would be called a _Chloride_.
Ions in Biological Systems
1. What is Cystic Fibrosis?
Faulty chloride ion transport results in buildup of mucus and fibers in lungs
2. What ion would someone with Menke’s disease have a buildup of in the kidneys and a
lack of in the brain and spinal cord? Copper
3. What is Hypokalemia? Hypernatremia?
Hypokalemia – Low levels of Potassium in the blood (comes from the Latin term for
potassium, Kalium)
Hypernatremia – High levels of Sodium in the blood (comes from the Latin term for
sodium, Natrium)