This week in class we took a test on Wednesday.  To prepare for the test we went over a unit 4 review.  We then went over this review sheet in class on white boards and went over our answers as a class.  It was our responsibility to check our answers and make sure they were correct.  The packet had roughly seven problems with subquestions to each one.  The packet went over everything we have learned for far for unit four.  It went over definitions, describing pictures, drawing particle diagrams, understanding the difference between monatomic and diatomic molecules, finding ratios and using the ratio to draw out particle diagrams and figuring out their formulas, and lastly the packet went over how to draw a graph representing when something boils out of a mixture based on temperature. A picture of this packet is shown to the left.  One of the last things we went over as a class before the test was a way to remember which elements are diatomic on their own.  The way we learned this was either the "7 up" method or BrINClHOF.

     Then immediately after we finished the test we were given a sheet with the objectives for unit five. Unit five is about counting particles, without actually counting them so we are just beginning to start this unit and we started off by weighting and seeing how we can use weight to determine how many particles are within a substance.  We practiced this by going over some practice problems in class and determining how exactly to go about solving the problem.  Dr. J also went over how to convert units from kg to g and so on.  We then learned about relative mass and how that works.  The math for that is shown here.  Then we also compared the relative mass to that of the element carbon for the washer, nut, and bolt.  By doing this we created different elements like, Sulfur for the bolt, Oxygen for the nut, and Carbon for the washer because the washer was just 1.00.



     This worksheet was used to show the ratio between oxygen and hydrogen.  It gave us the density of each at standard temperature and pressure.  The ratio was 16:1.  This represents how much more massive the oxygen molecule is compared to the hydrogen molecule.  We then had to draw the 16:1 ratio as best we could.

     We then compared Daltons relative mass theory to the adjusted mass.  We saw the difference in the table of masses that we made.  The main difference was that Dalton was not aware that oxygen is a diatomic molecule so his masses were half of what they should be.  This table was used to help show use that difference and to remind us that when using mass to count how many particles are in a substance, that we always have to remember the eight diatomic elements when weighting and drawing things out.  It's very important to closely analyze what elements are being combined and whats they individual mass is in order to properly figure out the total mass.
   
     This week a lot of new ideas were shown and demonstrated in class and so far I understand them fairly well.  I still need to work on converting units still using Dr. J's equation for more practice to understand the concept better.  However, besides that I understand the material very well and feel confident in my ability to do most of what we learned on my own.