Wednesday, November 17, 2010
Tues-Day 2
Physics - we applied the concept of impulse as the source of change in momentum to several problems in the Momentum 1 worksheet.
We saw that the variables Fnet, t, m , vi and vf can be manipulated to solve for any one variable given the other four.
AP Chem - Today, for most of you, was your introduction to truly UNDERSTANDING chemistry; it can actually make sense now!
We began the logical explanation of ALL atomic periodic trends and most chemical phenomena by defining and applying THREE FACTORS that all stem from COULOMB'S LAW.
Coulomb's Law states that electrostatic force between two particles is proportional to the quantity of charge on each particle and INVERSELY proportional to the SQUARE of the distance between the two particles. In English, the greater the number of protons, the greater the electrostatic force on an electron from these protons, and also the greater the distance between two charged particles, the LESSER the electrostatic force between them.
We applied this law to explain how increasing Zeff (effective nuclear charge, Z-S) causes a greater attraction on an electron and how an increasing number of OPEL's (OCCUPIED-by electrons-principal energy levels) will increase distance of valence electrons from the nucleus and thus decrease nuclear attraction on these electrons. We also saw that electron-electron repulsion within a given PEL/shell can cause electrons to "spread out" and increase the size of an atom.
We explained the trends in atomic radius across a period (from left to right) and down a group; we even explained the LACK of change in atomic radius across the transition metals part of a period.
We defined the term "isoelectronic" and gave examples of isoelectronic species.
We saw that the variables Fnet, t, m , vi and vf can be manipulated to solve for any one variable given the other four.
AP Chem - Today, for most of you, was your introduction to truly UNDERSTANDING chemistry; it can actually make sense now!
We began the logical explanation of ALL atomic periodic trends and most chemical phenomena by defining and applying THREE FACTORS that all stem from COULOMB'S LAW.
Coulomb's Law states that electrostatic force between two particles is proportional to the quantity of charge on each particle and INVERSELY proportional to the SQUARE of the distance between the two particles. In English, the greater the number of protons, the greater the electrostatic force on an electron from these protons, and also the greater the distance between two charged particles, the LESSER the electrostatic force between them.
We applied this law to explain how increasing Zeff (effective nuclear charge, Z-S) causes a greater attraction on an electron and how an increasing number of OPEL's (OCCUPIED-by electrons-principal energy levels) will increase distance of valence electrons from the nucleus and thus decrease nuclear attraction on these electrons. We also saw that electron-electron repulsion within a given PEL/shell can cause electrons to "spread out" and increase the size of an atom.
We explained the trends in atomic radius across a period (from left to right) and down a group; we even explained the LACK of change in atomic radius across the transition metals part of a period.
We defined the term "isoelectronic" and gave examples of isoelectronic species.
# posted by C @ 11:04 AM 
