12/13/10

Announcements: Study for test on Thursday.

Homework: chem packet (due Wednesday) , and finish double replacement lab

Today in class we worked on the Double Replacement Lab in class. Mr. Paek explained how to mix the elements to see if there would be no reaction or a reaction. To do the lab you need to set up a data table that shows all the chemicals. Like this.

Then you mix each chemical once with the ones on the the grid and mark an which ones have a reaction, if there is no reaction write NR.

Next scriber: Mike A.

12/8/10

Announcements: do your homework and study! Quiz tomorrow!

Homework: Complete chemthink tutorial and quesitons (chemical reactions)!

On this day (late arrival) we learned about different reaction types:

1) Single Replacement

2) Double Replacement

3) Synthesis

4) Combustion

5) Decomposition

During single replacement, one element replaces another element in a compound. This kind of reaction consists of three elements: AX+Y. In this case A and X attract because they have the opposite charges (+ and -) while Y has a possitive charge. During single replacement, the product will end up being AY+X because now element Y has replaced element X. Example:

Since both copper and iron have a positive charge, they switch.

During double replacement, the positive charged elements and the negative charged elements switch places. This kind of reaction contains 4 elements: AB+XY. In this case A and X have positive charges and B and Y have negative charges. During the reaction, these elements switch pairs: AY+XB. To make it simpler, here is another example. There are two couples: AB and XY. A(boy) decides he doesn't like B(girl) and starts dating Y, and vice versa. Another example:

During synthesis, a 2 elements join together to form a complex compound. This reaction type is much easier to learn. An example: A+B=AB.

During decomposition, a complex compound seperates into two elements. Its the exact opposite of synthesis. An example: AB=A+B

Combustion is the reaciton of oxygen gas with anything. Combustion always and only contains oxygen carbon and hydrogen. It is the easiest reaction to learn because the answer is always CO2 + H2O. After this, all you have to do is balance the equation. Example:

Next scriber... IS PEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEETER I.

12/06/2010

Announcements: We will have two quizzes, none will be dropped. Homework will be assigned.

Homework: None


In class we learned about chemical reactions, and how to solve them. We started the day with atom counting. In atom counting, you have a formula and you count how many of each element there are. Ex. (2C+2O) There are 2 carbons and 2 oxygens in this formula.


Also we studied reactions and how they look. Ex. (N2+O2) the diagram would have both nitrogens attached to each other while the two oxygens will be attched to each other. The reaction is that both nitrogen and oxygen split and go to the opposite. the final balanced formula would be 2NO.
















Finally we went over balncing equations. He told us that the whole point is to make both sides equal for it to be balcnced. Also another thing was that the reaction is the product. Ex. 2Al+3Pb(NO3)2 -------> 2Al(NO3)3+3Pb. The numbers in red are what make it even.
Next Scriber: Ross

11.22.10

Announcements:

1. Lab test tomorrow

2. Quizzes on Monday and Tuesday after break

3. Unit test on Wednesday (12/01)

Homework: none.

Today, we did a lab for most of the time, and then we took a quiz with our lab group. There were two parts to our lab: Part 1 - Solubility and Part 2 - Volatility and Surface Tension.

In part one, we were given six liquids. The six liquids were hexane, ethanol, pentanol, methanol, butanol and acetone. We put each one in their own test tube, and put a few drops of water down the side of each test tube. We had to determine if the liquid would mix immediately with the water and if they stayed mix after shaking the test tube. We also recorded down our observations.

After filling out the table, we answered two questions about this part of the lab. The first question was why doesn't hexane mix in either step 3 or step 5? In step 3, we recorded whether the two liquids mixed immediately. In step 5, we recorded whether the liquids stayed mix after they had been shaken. The hexane did not mix with the water in either steps. The reason for this is because water is polar, and hexane is nonpolar. Previously, we learned that "like dissolves like", and "unlike stays separate". Therefore, because water is polar and hexane is nonpolar, the two liquids did not mix.

The second question that was answered was to explain the difference in our results for ethanol and pentanol. We also had to answer which mixed more easily, ethanol or methanol.

We had several differences in our results for ethanol and pentanol. Both did not mix immediately. After shaking, the ethanol mixed with the water where as the pentanol did not completely mix with the water. We observed that after mixing, the ethanol was clear and kind of yellow, while the pentanol was white and hazy. The methanol also mixed more easily with water because the methanol is more polar than the ethanol.

In the second part of the lab, we had to measure how much each liquid spread out and how fast each liquid evaporated. We put a drop of each of the six liquids on the table. We ranked them in order of 1 to 7 with 1 being "spreads out the most" and "evaporates the quickest", and 7 being "spreadas out the least" and "evaporates the slowest". We learned that there was correlation between whether a liquid was polar or nonpolar, how much each liquid spread out and how fast each liquid evaporated. We answered three questions related to the second part of this lab.

For the first question, we had to explain how the amount a liquid spreads out is related to the polariy of that subance. From observing each of the liquids spread out and evaporate, we recorded data which helped us find the correlations. We found that the more polar a substance is, the less it spread out. For example, water is very polar, and it spread out the least. We ranked it number 7. On the other hand, hexane is very nonpolar, and it spread out the most. We ranked it number 1.

The second question asked us to explain how the rate of evaporation is related to the polarity of that substance. We found that the less polar a substance is, the faster it evaporates. For example, water is very polar, and it took the most time for it to evaporate. But hexane is very nonpolar, and it evaporated the quickest.

Our third question was to list other factors (other than polarity) that might influence the rate of evaporation. I think an important one is temperature. If we spill water, and it's not very humid or humid outside, it takes a lot longer for the water to evaporate than if it's hot and humid. So I think that the temperature plays an important role in how long it takes substances to evaporate.

After we finished our lab, we took a short quiz together with our lab group on things that we have learned recently. Tomorrow, Mr. Paek will try to find the "weakest link" in each group, and ask that person to explain how we got our answers.

Today in class Mr. Paek went over any questions we had about the Lewis structure.

The Lewis structure is the drawing we draw with the dots. Today we got new worksheets; we got pages 16-20 and, learned something new. We learned about molecularshapes, and how to draw the shape.

There are different names for these shapes: linear, trigonal planar, trigonal pyramid, bent, and tetrahedral.

The name of the shape is linear id its 180 degreesand is on one flat plane. The shape of a linear would look like this:

The name of the shape is trigonal planar is there are three bonds, no lone pairs, and are on one plane. The shape of a trigonal planar is:

The name of the shape is trigonal pyramid is there are lone pairs of electrons, and if it is three dimensional. It would be three dimensional because, the lone pairs would go on top and push the three other bonds downward, making the shape look like this:

The name of the shape is bent if there are two bonds and the lone pairs push the two bonds downward. A bent shape would look like this:

The last name we learned is tetrahedral. Tetrahedral is just like trigonal pyramid, but rather than the lone pair it has an extra bond. The extra bond will push the other three bonds downward. A tetrahedral shape would look like this:

When drawing any shape, first look at the Lewis structure of the element, and only draw in the dots for the center element, but draw in the correct amount of bonds. When drawing a trigonal pyramid the three bonds should be facing down because of the lone pairs of electrons forcing it to go downward. Also, the two pairs of bonds for the bent shape is also facing downward because of the lone pairs of electrons. Same with the tetrahedral, because of the extra bond it forces the 3 other bonds to go downward. (the pictures are shown above).

Homework:- finish pages 16-19 (new work sheets we got today) and the two worksheets given on Friday are due tomorrow for credit.

Upcoming quizzes or tests:- there is a quiz tomorrow. The test is after Thanksgiving break.

Next Scriber:- Tima Tito

11.18.10

Announcements:

1. Tomorrow is Chem-day in the Lyceum.

2. On Tuesday, the day before break, we will have our lab test for this unit.

AFTER BREAK

3. On Monday 11/29/10, we will have a quiz.

4. On Tuesday we will have another quiz.

5. On Wednesday, December 1, we will have our unit test.

Homework: none.

Today in class we first got pages 25 through 30. Then we officially begin the class by going over the worksheet that we worked on Wednesday with the substitute. There were two major problems that we worked on which were C2H2 and C2H6O. For C2H2, the correct Lewis structure was: H-C=-H. (The double bond is suppose to have another line on top, so after the C is three lines.) The second problem that students were confused about was C2H60. The Lewis Structure for this molecule is a bit too complicated, but it not something you should worry about so much.

Next we went over polar and non polar. As a reminder, polar means unequal or different, and non polar means equal or same. Make sure that you understand those two terms completely so that the future will be easy for you. After we reviewed a little bit about non polar and polar, we did page 25. Then we started a lab.

This lab starts on page 27 and is called "Polarity Olympics: The Trials". First on the page, we decided what the charge of each molecule was in H2O. The two Hs' have an electronegativity charge of 2.1 The oxygen molecule has a charge of 3.5 and because it has a higher electronegativity, it has a negative charge. The two hydrogen atoms have a positive charge. After doing the first page together as a class, we then finally began our lab.

(Page 27)

In the lab, we used a penny, water, hexane,watch glasses, capillary tubes, markers, and two cotton swabs. For the first part of the lab, we put many drops of water onto a penny until it overflowed. We recorded the number of drops and then drew a side view of the penny. We did the same procedure twice a second time, but instead of water we used a liquid called hexane. From our results, water had the most drops than hexane. We observed that hexane evaporated a lot faster than water did when it touched the table.

For the second part of the lab, we used capillary tubes and watch glasses. We put 10 drops of water onto one watch glass and hexane onto another. The we took the capillary tubes and touched them with each liquid separately. The capillary tube that held the most liquid was hexane.

The third part was easy just like the previous two parts. The point of this trial was to clean two types of marker from the glass. On one watch glass we drew a line with permanent marker and on the other, we drew on it with a transparency marker. Then we put water on a cotton swab and wiped the transparency marker. The transparency mark went away and the cotton swab turned green. With the same swab, we wiped the permanent marker, but it didn't go away. Next we put five drops of hexane onto a new cotton swab and wiped the transparency mark, but it didn't erase. When we wiped the permanent mark with the hexane filled swab, the mark went away. From our data, we concluded that water erased the transparency mark, but not the permanent mark and hexane erased the permanent mark , but not the transparency mark. The water and hexane were opposites.

This was the lab we did today and it was pretty easy. We ended the class by cleaning up our mess. Also our lab test is most likely going to be somewhat similar to this one! If you have any questions about anything, be sure to ask Mr. Paek for help!

Next Scriber: Petrina Z.

11.09.2010

ANNOUNCEMENTS: 1. There will be a total of 6 quizzes, one everyday 2. If you're absent before a quiz, that quiz will be the one that's dropped 3.You can drop one quiz and retake one quiz 4. We taped in pages 9 to 15

HOMEWORK: Finish pages 11 to 13

Today in class we learned how to make Lewis dot structures for formulas like CH4 or F2 and others like the examples below:

Before drawing the actual structure, Mr. Paek suggests doing N, H, S and B every time because it makes it a lot easier. These letters stand for Need, Have, Share and Bonds. 

• NEED: you put the number of electrons needed to be stable, for most elements it's 8, but for Hydrogen it's 2. Then add all of it together.
• HAVE: the number of valence electrons then add it all up. 
• SHARE: subtract the number of valence electrons from the sum of the electrons needed. 
• BONDS: you divide the number shared by 2.

For example: The formula SeF2

• N= 24 (Se needs 8 electrons and F2 needs 2 sets of 8 because of the subscript "2", so you do 8+8+8=24)
• H= 20 (Se has 6 valence electrons and F2 has 7 and 7 because of the subscript "2", then you do 6+7+7=20)
• S= 4 (N-H or 24-20=4)
• B= 2 (4 divided by 2)

Once you're done with all that, you have to draw the structure.Using the same formula SeF2, Se would be in the center with two F's on either side, it doesn't really matter what side it's on as long as there are two F's. The bonds represent the lines from Se to the F's. Each line representing the number of electrons shared, which in this case is four, so two lines represent four electrons shared. The picture also has to have 20 total electrons in it because of the have. Since the lines already represent 4 electrons, you need 16 more, so you draw dots around the Se and the F's. I know this may sound confusing, but the picture below should make it easier to understand. The formula I used for this example is the first one below:

NEXT SCRIBER: Seena K.

11.8.10

Announcements- 6 QUIZZES this chapter, Chemthink & Webassign MUST be done before class. We picked up the calender and pages 1-8 in class today.

Homework- Pages 1-8, except 3(most finished in class)

Today in class we learned about covalent bonds. We observed the “potential energy curve” with covalent bonds.




Using a graph like this, we explain that when two atoms are moved far apart to close together the potential energy of the two atoms decrease, making the stability (how stable the atoms are) increase. This would make the electrostatic force a proton-electron attraction meaning that one proton from one atom attracts an electron from the other atom.

When the two atoms move from close together to far apart the potential energy of the two atoms would increase, making the stability (how stable the atoms are) decrease. This would cause a proton-proton repulsion meaning that the protons repel as they get too close to each other.

Next in class we talked about naming covalent bonds. Covalent bonds are ONLY nonmetals. You don’t need to worry about figuring out the charges. When naming the first element NEVER has a mono, but the second one will.

We use these prefixes:
1-mono 2-di 3-tri 4-tetra 5-penta 6-hexa


If the element starts in a vowel and the prefix ends in a vowel take out the prefix vowel, for example Carbon Monoxide.

• Here are a few examples of naming covalent bonds:
CO- Carbon Monoxide
CF3- Carbon Tetrafluoride
N2O3- Dinitrogen Trioxide
AsCl3- Arsenic Trichloride

*Remember to still use –ide at the end of second element





When figuring out if it is an Ionic or Covalent bond look for these:

• Polyatomic Ions (SO4-, NO3-, NH4+, etc.)
• Transition Elements (Cu, Fe, Pb, etc.)
• Metals (Ca, Al, Na, etc.)

Here are some examples on figuring out ionic (I) or covalent (C) bonds and writing the formulas:

• Nitrogen Dioxide C NO3
• Copper(II) Phosphide I Cu3P2
• Sulfur Trioxide C SO3
• Chromium(III) Bromide I CrBr3








Next Scriber- Gennah L

11.2.10

Today in class, Mr. Paek went over a lot of important concepts for Thursdays test. He handed out review sheets for unit 4 before a short quiz. The quiz and review sheet went over some of the main ideas like whether or not the certain element will gain or lose an electron, different charges, compounds and chemical formulas.
**Important concepts:
1. Example: Chlorine: Element will GAIN 1 electron to become more stable.
2. Example: Sodium ions and oxide ions: Na2O
3. Example: CaBr2: Calcium Bromide

Some important rules to remember when studying for thursdays tests are the polyatomic ions: ***Sulfate, Nitrate, Phosphate, hydroxide, carbonate, ammonium, bicarbonate

After reviewing and taking the short quiz, we played Ionic Boggle!!! Ionic Boggle (hopefully we can play again!!) is where you try to make compounds with the elements you are given. You play it like boggle the only difference is the letters are now elements!

WEBASSIGN DUE THURSDAY, TEST THURSDAY.
Good luck to everyone on the test!!!! Study hard! :)

11. 1. 2010

• At the beginning of class, Mr. Paek collected any quizzed people needed to take home on Friday and the extra credit unit 4 packets. He also check in the homework that was assigned over the weekend which was pages 9-13 in the journal.
• We went over the homework (pages 9-13) and if people had any questions on the homework they were answered.
• Mr. Paek taught the class a short cut on writing the formulas for compounds. For example if the compound is cobalt (III) carbonate, since cobalt has a charge of +3 and carbonate has a charge of -2, in order to write the formula you can just switch the charge numbers, ex. Co2Ca3
• For the majority of class we worked on our journal pages alone and asked questions as needed.
• At the end of class we took a short quiz testing out ability to write compound formulas and name compounds etc.

Don't forget to read pages 253-258 in the book and answer question number 7 on page 258.

Also we have 2 web assigns.

10.29.10

At the beginning of first period, Mr. Paek tough us a little on ionic formulas and how to figure out the formulas for different compounds. For example, if we had a K+ and a O2- then we would need to get potassium's charge the opposite of oxygen and to equal zero. Here are some other Examples of ionic formulas:

Ex:
Co3+ and Cl- = CoCl3-
K and N= K3N



Mr. Paek also talked about Polyatomic Ions and their symbols. Polyatomic ions are ions that such as Sulfate, Nitrate, Phosphate, Etc... Mr. Paek also went over how to name the formulas Such as CaCl2 would be calcium chloride. He also noted that if there was a roman numeral in front of the first named element that it was the charge. After we walked everything trough we took a quiz on a few things we've already talked about its nothing to worry about. after the quiz Mr Paek assigned some homework.

Homework:
Worksheets handed at beginning of class. pages 11, 12, 13, and 14.

10.13.10

Wednesday: late arrival! :) 35 min period

At the beginning of the period, Mr. Paek showed us a few vidoes on metal reactivity. He explained how the periodic table consists of different families:
Row 1(downward) - Alkali metals
Row 2(downward)- Alkaline earth metals
D Block(sideways)- Transition metals

The vidoes consisted of experiments about the reactions of the alkali metals and water. The farther down the row in the periodic table, the stronger/more intense the reaction. In one of the videos, it included an experiment with a glass. The metals were put in the water one by one:
Li- Floated on the water while giving off hydrogen
Na- The same as Li, but a more vigorous reaction. Na gave off much more hydrogen
K- Produced sparks and a small fire
Rb- Produced bigger sparks and bigger fire
Cs- Completely shattered the glass cup

After watching the vidoes, Mr. Paek introduced a short lab. The metals that were being tested were calcium, magnesium, and aluminum. We placed these metals into well plates and used water, HCL, phenolphthalein indicator (PHTH) (liqiud) to see how they would react with the metals. Her is the data:
Appearance:
Ca- little rocks
Mg- thin metal sheets
Al- Flat rocks

PHTH:
Ca- water turns pink
Mg- magnesium sheet turns pink
Al- water becomes cloudy

Water:
Ca- sizzles and dissolves
Mg- nothing
Al- nothing

HCL:
Ca- sizzles and disolves a little
Mg- sizzles and gives of hydrogen
Al- nothing

PHTH and HCL
Ca- turns pink
Mg- nothing
Al- nothing

NO HOMEWORK!!!
Next Scriber: Sal :)

Friday October-1-2010

To start class Mr. Paek went over the previous days scribe post. Then he started giving us notes in the papers labeled Atomic Models. Then we started the fireworks lab.

PreLab: when electrons drop DOWN an energy level, they give off a specific amount of energy in the form of electromagnetic radiation. This energy then strikes our eye, causing chemical reactions in the eye that excite neurons and thus we perceive color. The electrons for metals in particular have energy levels far enough apart to cause colors in the visible spectrum

What does the statement, “Electrons can become excited,” mean?

The purpose was to observe the different quantum leaps of electrons in several metal salts. Basically at each lab station, there were cups of different salts, metal splints and a Bunsen burner. When we got the splint wet, we covered the end with salt, and stuck it into the flame. Depending on the salt, the flames changed colors like bright red, blue/green and others.

On the lab sheet, you had to describe the specific color given off by each metal salt and the go to the front of the room where Mr. Paek had 3 different unknown salts that he showed us on the bunsen burner and depending on the color and our resulfs from the other lab stations, had to deduct what they were. the bell rang before we finished the post lab questions so Mr. Paek just said we'd go over those on Monday. Happy Homecoming!

Thursday 9/30/10

part one of the lab
part two of the lab

data collected from lab completed in class

Today in class, we were given six sheets, two for the lab we did in class, the other four we didn't get to yet.

The lab todaywas the Rutherford Simulation Lab, in the lab we took a piece af paper with six circles on it, and six small squares at the center of each circle. We layed a piece of carbon paper on top, and with a partner, bounced a marble on top of the paper 110-120 times. After we finished, we counted the number of dots: in the circles, in the squares, and out side of the circles.

Using the collected information we found various data, like the percentage of dots that landed in the circles, for example me and my partner got 69 dots in the circle, out of 120 dots. to get the percent divide the number dots in the circle to the number of total dots: 69/120=.575 or 57.5%.

then using the total area of the paper, 93.5in. sq., and the percent of dots that landed in the circle, we found an estimated area of all 6 circles. We did this by multiplying the area of the paper times the percentage in decimal form: 93.5*.575=53.76in. sq.

Using the information we just found, we divided by six to find the next question, which was, what is the area of one circle: 53.76/6=8.96in. sq.

Then we solved to find the radius. To do this divide bothe sides by pi, then the square of your answer. To solve for diameter, multiply the answer you just got by 2. 8.96/3.14159=2.85 then the square of 2.85= 1.689in is your radius. 1.689*2= 3.378in is your diameter.

For problem 7, use a similar process to find the area of a square, like finding the area of a circle. First divide the number of dots in the squares by 120, i got 2/120=1.56, then divided by 6 to get one squarer alone. 1.56/6=.259in. sq.

to find the length of a side, take the square root of the area of one square.

Question Answers:


What does the paper represent?

the gold foil

What does the circle represent?

the atom

What does the marble represent?

the alpha-particle

What does the square represent?

the nucleus of the atom

The true diameter of each circle is 3.2 inches. find your percent error. to do this subtract your value minus the true value, then divide by the true value, and multiply by 100.

>>> (3.378)-(3.2)=.178/3.2=.055625*100=5.5625%

What could account for your own error in this lab?

>>>answers may differ. ex: not enough data collected.

Homework: Finish Question Four of the Lab, Test next Friday, October 8th, 2010

Next Scriber: Lauren

Wednesday 9/29/10

Modern View-electrons can be in ground or excited states and can jump between levels. When electrons drop levels (high to low) they give of a beam of light! Its like bees in a beehive and bees are electrons moving around the nucleus like a cloud. Similar to the picture above

Niel Bohr from 1914 discovered that electons(-charge) "ORBIT" around positive nucleus in different- ORBITALS(levels). Electrons can jump up and down these levels. As seen above.

Rutherford discovered all atoms have tiny positive centers(nucleus).

Ernest Rutherford from the early 1900's shot alpha particles(+ charge) through gold foil as shown in the picture above. Most of them went through but some deflected and these some were - charged particles!

Joseph John Thomson or J.J. from 1897 studied cathode ray tubes. He would excite the gas in the tubes with electricity. He would hold a magnet to the sides of the tube noticing a bend in the light (+ side attracted beam, - side repelled beam). He discovered that atoms must have a negative(-) charge and if that, then with overall neutrality, they must also have a positive(+) charge. This is demonstrated in his model above.John Dalton was an english schoolteacher from the early 1800's. He thought that each element was mad of elements, an atom of one element would be identicle to an atom of the same element. Also atoms do not include the existence of the nucleus, dosen't explain the existence of ions or isotopes, and dose not talk about subatomic particles (electrons, protons, and neutrons). His view of the atom looked something like the picture above.

Today we started off class by finishing the notes from yesterday on the Atomic scientists (Dalton, Rutherford, Thomson, and Bohr). You may look at yesterdays scribe for what they look like and foe more help.

After that Mr. Paek gave a lecture on the four scientists, their major contributions, what they discovered about the atom, and their actomic model. As shown above^ NOTE: start from the bottom picture and read up!!

no homework! lab test due by next friday!

Next Scriber: Maddy M.

Tuesday 9/28/10

Black container that contained the bead. There were 12 different containers with differents line patterns inside of them.
(scroll down all the way for more details)

Black box lab

We did this sheet in class. The sheet had four atom scientists' names and we had to fill out information about them. The information can be found on the colored sheets pictured below.

These are the colored sheets of paper with the information on  four atomic scientists. (Dalton, Rutherford, Thomson, Bohr)

2nd part of the black box lab

Today in class, we started a new unit. We began studying the atomic theory. We did the Black Box Lab. In this lab, we had to go to several stations with black circular containers. Each container had a bead inside of it. We would rattle and move the container to determine what type of shapes/lines were inside of the canister. We could determine the shapes by feeling how the bead bounced off the surfaces, and how the bead sounded when it bounced off certain spots of the container. We weren't allowed to open up the container to see the shapes.Then, we would sketch what we guessed was in the container, on our lab sheet. It was sort of like the concept of trying to figure out what atoms looked like, back in the days of Dalton, Rutherford, Thomson and Bohr, who were atomic scientists.

We got four colored pieces of paper with information about 4 different atomic scientists. The information on the sheets of paper can be used to fill out the Atomic Scientists worksheet that we got to do in class.

Next Scriber: Grace Ridge

No homework. Test next Friday, October 8th, 2010

9.27.10

Today in class we did not do anything complicated. It was an easy day and we reviewed the test that we took last Thursday. We also talked about the lab test that we took last Wednesday.

First of all, we started off by getting our journals back from Mr. Paek. He was supposed to check them in for points, but he did not yet because he was a bit too busy. To get an A for the journals just make sure the pages don't fall out and that they should be in a similar order to Mr. Paek's journal. We also got four new pages for our journal for unit two. (The new pages are shown at the bottom.) Please leave a blank page after the first two pages to have a page titled, "Text Questions." He also crossed out the names of people who were scribers, so if you were a scriber already, make sure you tell Mr. Paek.
Afterwards, Mr. Paek said that there were good news and bad news. The bad news was that the class did not do a good job on the lab test. Since our class did poorly, he is giving us an opportunity to get half the points back from the lab. In order to get the points back you can go see Mr. Paek during 5th period, 6th period, before school, or after school to work on a worksheet based on the lab test. You have one week to get points back from the lab test, so the option to do the lab worksheet is open until next Monday October 4th. The good news is that the test results were great! We got back our tests today and went over a few problems. After getting back our test, we also got a grade report. As a reminder, remember that labs/projects are worth 20% and tests/quizzes are worth 50% of your chemistry grade.

--The four new pages:

This is all what we did during class today. If you have any questions make sure to ask Mr. Paek. Also, don't forget to get the four new journal pages! There is no homework tonight!

-Next scriber: Alyssa P.
****When you're done with writing your own scribe post, please write the name of the next scriber that you choose.

The Scribe List

This is The Scribe List. Every possible scribe in our class is listed here. This list will be updated every day. If you see someone's name crossed off on this list then you CANNOT choose them as the scribe for the next class.

This post can be quickly accessed from the [Links] list over there on the right hand sidebar. Check here before you choose a scribe for tomorrow's class when it is your turn to do so.

IMPORTANT: Make sure you label all your Scribeposts properly (Your display name, unit title, scribepost, and p1chem2010) or they will not be counted.

Michael            Lauren          Danny          Jennifer               Erika          Ross          Nik          Sal           Lia          Heather          Seena         Gennah          Dan          Cyril          Maddy           Emily          Alyssa          Josh          Grace          Michelle          Brandon         Tima          Petrina          Peter

Friday September 17, 2010

Today in chem we did a lab titled "Matter Lab Stations", learned about diatomic molecules, and completed a chapter 1&2 review sheet. For the lab, all of the tables had models of molecules and atoms made of different colored balls (pictured below). We went around all 6 tables, and completed a sheet that required us to draw a picture, write a formula, and list all the terms that applied.

The terms we used were;
Atom, Molecule, Pure substance, Mixture, Compound, and element.

We were told that;

yellow-Hydrogen

black-Carbon

red-we could choose any element, but the majority of the class chose Oxygen.

When we finished Mr. Paek went over it with the whole class.

Diatomic Molecules
After we went over the lab Mr. Paek told us about Diatomic Molecules. The definition we got was: these elements will always be paired when by itself. In other words, when you see one of these elements it will always have a subscript of 2 when it is by itself, i.e. cannot be just one atom, it must be a molecule.

The diatomic molecules are

H-hydrogen

O-oxygen

N-nitrogen

Cl-chlorine

Br-bromine

I-iodine

F-fluorine

Another way to remember these is by combining them to make a word 'honclbrif' pronounced hohn-cul-brif.

Review
The review sheet included:

density

conversion factors

molecules, atoms, compounds, elements

chemical and physical changes

states of matter

metric estimations

All of these will be included on the quiz on Monday, and the test on Thursday. There is a lab quiz on Wednesday also. Dont forget: the web assigns are due on Monday!