Wednesday, September 26, 2007
Wednes-Day 2
Bio- REMINDER: the text section 6.3 outline hw is due on Thursday.
We discussed the fundamentals of chemistry starting with the components of an atom: the nucleus of protons and neutrons surrounded by electrons that are in specific energy levels. We drew and explained how and why atoms bond together to form a molecule e.g. how two atoms of H bond to one atom of O to form H2O.
Related to today's lesson, there is a powerpoint on atoms, molecules, and bonding on Blackboard now in the "Course Documents" section.
Also, a "Biochemistry Unit Goals" document is posted there.
We will discuss atoms, bonding, ions, and formation of mixtures, tomorrow.
Chem 7/8- we finished discussing the four techniques for separations of mixtures of substances based on the components' differences in PHYSICAL properties: filtration (solubility), distillation (boiling point), chromatography (degree of attraction to a given solvent/mobile phase), and crystallization (degree of solubility at a given TEMPERATURE... p.s. crystallization has NOTHING to do with density).
We further contrasted physical and chemical changes and related them to physical and chemical properties i.e. a PHYSICAL change results in a change in a substance's PHYSICAL properties but NOT in its CHEMICAL properties; a CHEMICAL change literally changes a substance into a DIFFERENT substance (different chemical formula) with DIFFERENT physical AND chemical properties! We then witnessed a CHEMICAL change as we observed the formation of a black lump of carbon (as well as water vapor) from the reaction of sugar and sulfuric acid.
We then began our new unit on energy and phase changes of matter by defining energy and discussing the various kinds of POtential energy (due to the relative POsitions of particles) and kinetic energy (the energy of motion).
The THREE lab write-ups are to be handed in by Friday.
Chem 9- we did further lab catchup (I have one more item to discuss with you for that, tomorrow) so that the THREE lab write-ups can be handed in on Friday.
We then discussed two techniques for separations of mixtures of substances based on the components' differences in PHYSICAL properties: filtration (solubility) and distillation (boiling point). We further contrasted physical and chemical changes and related them to physical and chemical properties i.e. a PHYSICAL change results in a change in a substance's PHYSICAL properties but NOT in its CHEMICAL properties; a CHEMICAL change literally changes a substance into a DIFFERENT substance (different chemical formula) with DIFFERENT physical AND chemical properties!
We will discuss the other two separation techniques: chromatography (degree of attraction to a given solvent/mobile phase), and crystallization (degree of solubility at a given TEMPERATURE... p.s. crystallization has NOTHING to do with density).
We discussed the fundamentals of chemistry starting with the components of an atom: the nucleus of protons and neutrons surrounded by electrons that are in specific energy levels. We drew and explained how and why atoms bond together to form a molecule e.g. how two atoms of H bond to one atom of O to form H2O.
Related to today's lesson, there is a powerpoint on atoms, molecules, and bonding on Blackboard now in the "Course Documents" section.
Also, a "Biochemistry Unit Goals" document is posted there.
We will discuss atoms, bonding, ions, and formation of mixtures, tomorrow.
Chem 7/8- we finished discussing the four techniques for separations of mixtures of substances based on the components' differences in PHYSICAL properties: filtration (solubility), distillation (boiling point), chromatography (degree of attraction to a given solvent/mobile phase), and crystallization (degree of solubility at a given TEMPERATURE... p.s. crystallization has NOTHING to do with density).
We further contrasted physical and chemical changes and related them to physical and chemical properties i.e. a PHYSICAL change results in a change in a substance's PHYSICAL properties but NOT in its CHEMICAL properties; a CHEMICAL change literally changes a substance into a DIFFERENT substance (different chemical formula) with DIFFERENT physical AND chemical properties! We then witnessed a CHEMICAL change as we observed the formation of a black lump of carbon (as well as water vapor) from the reaction of sugar and sulfuric acid.
We then began our new unit on energy and phase changes of matter by defining energy and discussing the various kinds of POtential energy (due to the relative POsitions of particles) and kinetic energy (the energy of motion).
The THREE lab write-ups are to be handed in by Friday.
Chem 9- we did further lab catchup (I have one more item to discuss with you for that, tomorrow) so that the THREE lab write-ups can be handed in on Friday.
We then discussed two techniques for separations of mixtures of substances based on the components' differences in PHYSICAL properties: filtration (solubility) and distillation (boiling point). We further contrasted physical and chemical changes and related them to physical and chemical properties i.e. a PHYSICAL change results in a change in a substance's PHYSICAL properties but NOT in its CHEMICAL properties; a CHEMICAL change literally changes a substance into a DIFFERENT substance (different chemical formula) with DIFFERENT physical AND chemical properties!
We will discuss the other two separation techniques: chromatography (degree of attraction to a given solvent/mobile phase), and crystallization (degree of solubility at a given TEMPERATURE... p.s. crystallization has NOTHING to do with density).
# posted by C @ 8:37 AM 
