Saturday, November 17, 2007
Fri-Day 2
Bio- we discussed the Transcription and Translation Lab, reviewing the definitions. We also reviewed the order of events in those processes and then we reviewed the types of mutations.
Work on your review sheets this weekend. I will post an additional list of review questions on Blackboard.
Chem 7/8- we reviewed the similarities and differences among isotopes of an element. We completed the hw packet chart on isotopes. We further discussed ions noting that METALS tend to LOSE electrons to become positive cations BUT NON-METALS tend to gain electrons and to become negative ANIONS (not "onions"). We noted the convention for writing the symbol of an ion: value of the charge first, THEN the positive or negative SIGN to the right of the value (the opposite order signifies "oxidation state" instead of true electrostatic charge).
We then demonstrated how to calculate a WEIGHTED AVERAGE and applied this method to getting the ATOMIC MASS of an element. The atomic mass of an element is just the weighted average of the masses of the elements naturally occurring isotopes (based on their percent "abundances" as found in any natural sample of that element).
It is important to practice the setup and calculation of atomic mass.
I gave out a classwork packet. Continue to work on that for hw this weekend.
Chem 9- we reviewed the similarities and differences among isotopes of an element. We completed the hw packet chart on isotopes. We further discussed ions noting that METALS tend to LOSE electrons to become positive cations BUT NON-METALS tend to gain electrons and to become negative ANIONS (not "onions"). We noted the convention for writing the symbol of an ion: value of the charge first, THEN the positive or negative SIGN to the right of the value (the opposite order signifies "oxidation state" instead of true electrostatic charge).
I gave out a classwork packet. Continue to work on that for hw this weekend.
Work on your review sheets this weekend. I will post an additional list of review questions on Blackboard.
Chem 7/8- we reviewed the similarities and differences among isotopes of an element. We completed the hw packet chart on isotopes. We further discussed ions noting that METALS tend to LOSE electrons to become positive cations BUT NON-METALS tend to gain electrons and to become negative ANIONS (not "onions"). We noted the convention for writing the symbol of an ion: value of the charge first, THEN the positive or negative SIGN to the right of the value (the opposite order signifies "oxidation state" instead of true electrostatic charge).
We then demonstrated how to calculate a WEIGHTED AVERAGE and applied this method to getting the ATOMIC MASS of an element. The atomic mass of an element is just the weighted average of the masses of the elements naturally occurring isotopes (based on their percent "abundances" as found in any natural sample of that element).
It is important to practice the setup and calculation of atomic mass.
I gave out a classwork packet. Continue to work on that for hw this weekend.
Chem 9- we reviewed the similarities and differences among isotopes of an element. We completed the hw packet chart on isotopes. We further discussed ions noting that METALS tend to LOSE electrons to become positive cations BUT NON-METALS tend to gain electrons and to become negative ANIONS (not "onions"). We noted the convention for writing the symbol of an ion: value of the charge first, THEN the positive or negative SIGN to the right of the value (the opposite order signifies "oxidation state" instead of true electrostatic charge).
I gave out a classwork packet. Continue to work on that for hw this weekend.
# posted by C @ 10:10 AM 
