3.15.11

Announcements: Our test for this new section will either be on Friday the 25th, or Thursday the 24th depending on which day we have a Chem day. Mr. Paek also informed us that we only have 2 more major sections and then we're home free, which is extremely exciting.

In Class: Today in class we did the Heating Curve Lab:

Items Needed: Beaker filled 1/2- 2/3 way with ice, hot plate/burner, thermometer in Celcius.

Procedure: We took a beaker filled with ice cubes and put it on a hot plate/burner. We then every 30 seconds wrote down the temperature of the water at the time. After the ice had melted you were still supposed to write the temperature, up until 3 minutes after the water had started to boil. When you're done with this, you need to make sure that you write down the temperatures and times. Then you needed to answer the usual questions on the sheet and make a graph with the time on the X-Axis and the temperature Y-Axis. (Reminder: Have a title for your graph, and name the x and y axis. Mr. Paek said he'd be grading these for accuracy)

Homework: Finish the graph and answer the questions!

Announcements : No Announcements Today.

Homework: None. You should have pages 1-8 already completed.

Today In Class : We did not do much in class. To start of class we grabbed pages 9-35 and taped them in our journals. The pages went about two pages per paper. Before taking the first quiz out of 7, we reviewed a little bit. we talked about how to convert grams molecules atoms and moles. We then took the quiz.

There is a total of 7 quizzes. each worth 7 points. 49 points possible. if you get 7 perfect scores you will receive extra credit. also if you receive 5 perfect you will get extra credit but a little less. same goes for 6 perfect scores. You will need to get at least one perfect score to take the end test.

To end class we had a power point on stoich. for the power point we worked on page 10.

Wednesday, January 26, 2011

Announcements : -If you have any questions about moles find Mr. Paek ( he is free 5th and 6th period.) This is a really important unit and if you want to do good on the test you have to do good on the quizzes.

-Make sure to show all work and units in homework and quizzes, because it will get very confusing later on if you don't get in the habit of doing it right now.

- Buy a notebook if you haven't already.

- First quiz tomorrow/ 7 quizzes total this unit.

Homework: -pages 7-8.

Body: Today in class we went over some problems from pages 1-6.(Again: make sure that you go get help from the TLC or Mr. Paek if you don't get something.) Then we did a lab called: Moles Stations Lab. The lab had 9 stations, and in each one of them we calculated either the mass number, mole, or the number of atoms.

Set1: had to count the number of pairs of shoes in the room.

Set2:find the mass of Aluminum foil and find its mass number and how many moles it had.

Set3:find the mass of a carbon rod find mass number of it and how moles, then how many atoms.

Set 4:we had to find how many moles of Krypton in a graduated cylinder, and the mass of it.

Set 5:we had to find the mass of H2O, and the number of grams in one mole of H2O.

Set 6:find one mole of HCl, the number of moles in it, and the number of molecules.

Set 7:found the volume of an aluminum bar its density and the number of moles and atoms.

Set 8:find the mass if neon, and the number of atoms in it.

Set 9:find the mass of a balloon and the balloon's mole.

***examples from some problems in the lab:***

set 2: 1)The mass of Aluminum foil=3.74g

2) The mass from the periodic table = 27 g/mole

3)Number of moles Aluminum foil has=3.74 g Al foil*1mole/27g of Al foil=0.14 moles of Al.

set3: 1) Mass of carbon rod= 4.35 g

2)Mass from periodic table= 12 g/mole

3)Number of mole in this carbon rod= 4.35g carbon rod* 1mole/12 g carbon rod=.36moles

4)Number of atoms in rod=.36mol*6.02E23atoms of carbon/1mole=2.16E24 atoms of carbon

Tuesday, January 25, 2011

1/25/11

Announcements - The first of quiz in this unit will be his Thursday.

Today In Class - Today in class we started by picking up some new pages for our notebooks. We then went over the lab from yesterday that was supposed to be finished for today. Mr. Paek went over some of the problems and also made sure that everyone knew what they were doing. Once we finished going over the lab, Mr. Paek showed us how to find the molecular mass of a compound. For example, the compound NH4Cl . The name of this compound is ammonium chloride. To find molecular mass of a compound, you start by finding the atomic mass of each element. In ammonium chloride, N has 14. H is one, but since there are four H's, you would really have four H. There are also 35.5 Cl. After you have found all of this, you add it all together. Once you have added it all together, you will end up with 53.5 g/mol. After we were showed molecular mass, we went over conversions one more time.

Homework - The homework for today is every problem on both page one and page two. On page three, you only have to do problem one both a and b, and problem two both a and b. On page four, you have to do all of problem three, four, and five. On page five you have to do problem one, letters e, f, g, h. The last page you have problems to do for homework is page six. You have to do problem two, letters d, e, f, and g.

THE NEXT SCRIBER WILL BE.................... yassine

1/24/11

Announcements- There will be 6-7 quizzes this unit. If you get 5-6 perfect scores then you will get some extra points added to your quiz category. Also, in order to take the final test, you must have a perfect score on at least 1 quiz you take. If you fail to do so, Mr. Paek will not let you take it with the class until you do.

Today In Class- Today in class, after rejoining us to the class again and welcoming any new students, we were introduced to the mol. A mol is 6.02 x 10 to the 23rd power. We were also told that a pair=2 and a dozen=12. Then we did a lab that worked on using Unit Analysis for finding the number of atoms in a certain number of grams, the number of grams in a certain number of mols, and the number of mols in a certain number of grams. An example of a question for finding the number of grams would be: How many grams would 3.01 x 1023 atoms of Al (26.98 grams) be? 3.o1 x 1023 atoms x 26.98 g
6.02 x 1023 atoms
Then you would cancel out atoms and do the math.

Homework- Finish the lab. We're going over it in class if you have any questions.

THE NEXT SCRIBER WILL BE....... paul mcmahon

12/8/10

Announcements

• Quiz tomorrow on balancing
• Possibly a quiz on Friday so be ready
• Test on the last Thursday before break

What We Did In Class

Today in class we first went over the homework we had the night before, which was pages 8 and 9. If you didn't do it, you probably should. It's good practice. We asked questions about it in class and got many questions cleared up. We then basically reviewed of what we learned yesterday, and elaborated more on each subject. We went over single replacement (p. 13), double replacement (p. 14), Decompostion (p. 15), synthesis (p. 16 &17), and Combustion (p. 17).

Before I describe anything we did today for you, I want you to know 1 trick that is needed every time this happens. Whenever the elements Hydrogen, Oxygen, Nitrogen, Chlorine, Bromine, Iodine, and Florine appears alone in an equation, always put a 2 after it. This is how it is used in nature so it is needed in the writing part too. A way to remember this is HONClBrIF and sound it out.

When going over single replacement, you need to find out which elements are positive or negative ions. If there are 2 positives and 1 negative, then you switch the negative from the one positive to the other. And then of course, balance it out. For example, if you had the formula: ZnS+ O2--->_____. Zn is positive, S is negative, and O is negative. So therefore, on the other side, it would be ZnO2 +S. But then you would have to balance it. So on the right side it would be 2ZnO because on the left it says there are 2 atoms of O (O2). And since I had to change that on the right, on the left it would be 2ZnS, which means on the right I would change it to 2S.

For double replacement, you do the exact same thing as single, except there will be 2 positive ions and 2 negative ions. So you would just swap them and balance them out again.

When doing decomposition, one compound splits up into 2 different ones. For example AB---> A + B. When using elements, an example would be HgO---> Hg + O2. or MgCl2---> Mg + Cl2. Make sure to balance them at the end.

Synthesis is the exact opposite of decomposition. Just put them back together. A + B---> AB. An example using elements would be K + Cl2---> KCl. Mg + O2---> MgO. Make sure that they're balanced at the end.

Finally, we have combustion. This is when there is a carbon atom, hydrogen atom, and oxygen atom all in the same equation. The answer for every single one would be CO2 + H2O no matter what. But the hard part about this is balancing them out. The easiest and smartest way to do this is by using the CHO rules. This is the order of balancing out the equation. Carbon, Hydrogen, and Oxygen. CHO. You won't forget.

Homework:

Page 10 in your journal

-------------------------------------------------------------------------------------------------

THE NEXT SCRIBER WILL BE........... VIT

11/22/2010

Announcements- Lab Test tomorrow.

Homework- Do the analysis questions from today's lab. Look over your labs to study for the test.

In class today we did the Polarity Olympics lab.

-Part one- Solubility.

In this part of the lab, we want to see if hexane, ethanol, pentanol, methanol, butanol, and acetone mix with water.

~This is what it looks like if it does not mix with water. There is a split between the different solutions.

After we do this, We see if it mixes immediately. If it does not mix we have to put a stopper on the test tube, shake it, and then see if it mixes then.

-Hexane- Does not mix immediately, Does not mix after shaking.

-Ethanol- mixes immediately, It stays mixed after shaking.

-Pentanol- Does not mix immediately, Does mix after shaking.

-Methanol- Does not mix immediately, Does mix after shaking.

-Butanol- Does not mix immediately, Does mix after shaking.

-Acetone- mixes immediately, Stays mixed after shaking.

-Part two- Volatility and Surface Tension

In this part of the lab we want to see which solution spreads faster and which solution evaporates the fastest. What we do is we put a drop of each liquid on the lab table and see which one spreads more and which one evaporates faster. 7th being spreads out the least and evaporates the slowest.

Liquid Spreading rank Evaporating rank

-water 7 7

-hexane 1 2

-ethanol 5 4

-pentanol 6 3

-methanol 4 5

-butanol 3 6

-acetone 2 1

The liquids that spread out more are non polar and the liquids that spread out the least are polar because the atrraction is has on the solution gets the solution closer together and holds it together more. Also if something is more polar, then it will evaporate the slowest because sticks more together to the table. That is why hexane evaporates faster, it is because it is non polar and there is no attraction to it that holds it down and together.

The next scriber will be Mahak =]

11/18/10

Announcements: Chem day tomorrow 11/19/10 in the lyceum

Quiz on Monday

Lab test on Tuesday

Homework: None

In the beginning of class we learned about polar and non-polar molecules. Polar molecules can not be split while non-polar can. If the molecule is bent it will always be polar. Just because it has polar bond does not mean it is a polar molecule.

The Lab: In the lab we put drops of water and hexane on a penny. The penny was able to hold more drops of water than hexane because it is a polar molecule. Polar molecules like to clump together because of the opposite charges within itself attract each other.

We also put drops of water and hexane in a watch glass and then put a thin glass tube (called a capillary tube) upright and covered the top of the tube so the liquids would go up the tube. The water went up further and stayed in the same spot when we tipped the tube back and forth. While the hexane didn't go up as far and would move around when tilted. Since the water molecule stayed in the same spot, the glass molecules are polar. This is because it attracted the water which is polar and did not attract the hexane because it it non-polar and likes attract likes.

In the last part of the lab we drew two lines on a watch glass. One of the lines was with a transparency marker and the other with a permanent marker. When we use the cotton swab with water on it the transparency line came off and the color leaked onto the swab. It also cleaned up all of the permanent line. Then we drew two more lines on a watch glass and put hexane on a different cotton swab. When we wiped the transparency line it did not come off and the line stayed on the watch glass. When we wiped the swab on the permanent line it came off. The ink in transparency marker is polar because the water(polar) was able to be wipe up while the hexane(non-polar) was not able to pick up the transparency line.

The next scriber will be Elizabeth.

11.16.10

ANNOUNCEMENTS: We took a quiz today, pick up pages 21-24 if you were not here, and I think that is it.

HOMEWORK: Page 24

Today we learned about different types of bonds that are related to electronegativity. Electronegativity as you may remember, describes an element's tendency to "hog" electrons (pull them closer to themselves than the other atom). We got a periodic table that has each element's electronegativity.

The three different bonds we learned were:

Purely covalent/non-polar: In this bond, neither atom has that much of a stronger pull than the other. The difference between the electronegativites of the two atoms will be 0.0-0.4

(*To find the electronegativity difference just subtract the smaller electronegativity from the larger one. EX: Carbon has an electroneg. of 2.5, Hydgrogen has an electroneg. of 2.1 so the difference is .4 This would be a non-polar covalent bond.)

Polar covalent: One atom has a slightly larger electroneg. causing it to have a stronger attraction to more electrons. Difference of electroneg. is 0.5-1.6

(EX: Hydrogen is 2.1, Oxygen is 3.5. The difference is 1.4 so it is polar covalent.)

In both of these, electrons are shared.

Ionic: In an ionic bond, one atom has a significantly larger attraction to the electrons than the other. In this case electrons are transferred. The range for this is 1.7 or greater.

(EX: Sodium is .9 and Flourine is 4.0 The difference is 3.1 so it is ionic)

We also learned how to identify atoms with a partial positive and a partial negative charge.

The atom with the greater electronegativity will have a partial negative charge because there are more electrons going towards it. And the partial positive atom has the smaller electronegativity because there are less electrons attracted to it.

Mr. Paek taught us the symbol that is used for this.

Disregard the second picture, he did not teach us that. The S looking thing is the symbol. If it's partial negative then a - sign will follow the symbol. And if its partial positive then it will be a + sign. In this image, hydrogen has an electronegativity of 2.1 and flourine has one of 4.0 Because flourine's electroneg. is greater, more electrons are attracted to it so it has a partial negative charge.

That's all folks!

Oh and the next scriber shall be Jillian (:

Monday, November15, 2010

11/15/2010

Announcements:

-Test will be on Wednesday after thanksgiving break.

-Web assigns are due Tuesday after thanksgiving break.

-Mr. Paek said he will not return our quizzes, but we get to retake one and drop the lowest.

-Mr. Paek also said that if there is anyone who doesn't get the lewis structure, they should go see him ASAP because it's important. The lewis structure is a key concept and you have to completely get it in order to understand upcoming lessons.

Homework:

-Finish up to page 19.

- Make sure you finish the 2 practice sheets we got on Thursday that go along with the chem think.(they might be collected tomorrow.)

In Class:

Well first Mr. Paek introduced to us the concept of VSEPR. He said that he will use this term a lot and he wants us to understand it. here is what each letter stand for:

-V= Valence

-S= Shell

-E= Electron

-P= Pair

-R= Repulsion

-This theory is used to prove that electron want to repel as far away from each other as possible.

-there are 5 types of molecular shapes: linear, bent, trigonal planar, trigonal pyramid, tetrahedral.

*Linear and bent are usually associated with 2 electrons and are are usually 2 dimensioned . (example by Mr. paek: If Mac and Kevin were to have a fight where would they go in the room to be as far away from each other as possible? the answer was in the corners of the room.)

*Trigonal planar, trigonal pyramid, and tetrahedral are associated with 3 electrons and are usually 3 dimensioned.(example by Mr. paek: if Max, Kevin, and Jimmy were to fight over kinga, where would they want to be in the room in order to be as far away from each other as possible? the answer was 2 would be in each corner and one would be in the middle)

- those were examples to help us visualize and help us understand what molecular shapes look like.

-Other key things to remember is that the lone pairs are key because they push everything down and change shape. And for shape you don't need dots unlike lewis structure.

- The picture at the right is page 16: I am going to go over the first one, so you guys get an idea on what we did today.

CS2

Needs: 24; Has:16;Shares:8; Bonds:4 .

I am sure we all know how to draw the lewis structure for this one ( see Mr. Paek if you don't), well the molecular shape is the same as the lewis structure but without the dots. and the name of the shape is linear.

The next scriber will be Andrea.

11-10-10 11-14-10

THURSDAY

Announcements: total review. don't forget you can drop your lowest quiz that we take.

Homework: none!!

Class: On Thursday we had a total review day. we reviewed all lewis structures, also went over homework pages 11,12,13. Then we took a quiz. after the quiz, we finished all the pages in our notebook.(up to 15) we worked on the pages all through class. most people had 10 minutes to spare at the end.

FRIDAY

Announcements:You can drop one quiz.

Homework: Finish chem think(if not finished in class) and finish the 2 practice pages.

Class: In class on Friday we went to the computer lab to work on chem thinks. The name of the chem think is "Molecular Shapes". This can be found under Covalent Bonding. It started of by explaining what VSEPR stands for. VSEPR stands for Valence Shell Electron Pair Repulsion. When you get atoms in a molecule, the bonds in the electrons repel each other. when more are added the atoms repel so they can get the furthest away from the other atoms.

While working on this chem think we had to answer a work sheet. A covalent bond is electrons being shared by two atoms. Electrons are found in the middle of the two atoms when in a covalent bond. When two atoms are bonded to a central atom the angle between them is a 180 degrees. when there are 3 is is 120 degrees. for four atoms bonded to a central atom it is 109.5 degrees.

While working with molecular shapes there are (as you can tell in the title) many different shapes. when there is just two to a bond the shape is linear. when it is in two dimensional with three atoms it is called trigonal planar. If their is a lone pair of electrons, it doesn't affect the atom but it does make the atom bent. the shape is called bent. when their is three atoms and it is three dimensional the shape is called a tetrahedral. again with lone electrons and three atoms the shape is called a trigonal pyramid.

after we finished the tutorial we moved on to the question set where you have to answer ten correct with getting 2 or less wrong. if you get three wrong you have to start over again.

Next scriber will be...... YASSINE!! (you know why)

11.9.2010

Announcements:

-During Unit 5, we will take 6 quizzes and be able to drop the lowest score.

-We took quiz #1 today.

-We will take quiz #2 tomorrow.

-We received pages 9-15 today.

Homework: Finish pages 9-15

Class: Today, we started off by doing a quick question and answer about what material was going to be on the quiz. After this, we then took our first quiz of unit 5. Once everyone had finished the quiz, Mr. Paek showed us what the answers were and went over them with us. The quiz was out of 8 total points with each question being worth half of a point.

We then started going over pages 9-15.

Page 9: This first page was Guidelines for Drawing Lewis Structures. What you first must do when you are drawing the Lewis Structures is to count the total number of valence electrons in the compound. If you are finding the structure of an ion, remember to add electrons for a negative charge and subtract electrons for a positive charge. Secondly, you should predict the arrangement of the atoms in the molecule, drawing a line to represent a single bond between each pair of bonded electrons. Thirdly, you should find the number of valence electrons left over after forming single bonds. The fourth step is to place electrons around the outside atoms until each is surrounded by eight electrons (the octet rule). H is the only element which does not follow the octet rule. The final step is to place any left over electrons around the central atom.

Page 10: Lewis Structures 1

-Ex: What is the Lewis Structure for CH4

Ans: What you would do would be to find out the needed electrons, how many electrons the compound has, how many electrons are shared, and how many bonds there are. In this instance there are 8 electrons needed for C. There are also 8 electrons needed for H4 because H needs 2 electrons and since there are 4 of the H electrons that makes 8. If you add 8+8 you will get 16. Therefore this compound needs 16 atoms. Next, is the amount of electrons they have. H4 has 4 electrons combined, and C has 4 electrons. That gives you 8 more electrons for 16. Therefore, they have 8 electrons shared. Then, you divided the shared electrons by 2 and you get the amount of chemical bonds. Then you need the formula. For this atom the formula would be H

/

H-C -H

/

H

Page 11: This is just a page of practice problems

Ex: H2O

Ans: There are 12 electrons needed, there are 8 electrons between H2 and O. There are 4 electrons shared. There are 2 bonds. Based upon this information, the formula would look like this ..

H-O-H

..

Page 12: Lewis Structures 2

Ex: Which elements are allowed to break the octet rule?

Ans: Elements allowed to break the octet rule if they do not have a full shell of valence electrons.

Ex #2: Does element A violate the octet rule?

/ / /

A

/ / /

Ans: Yes because each of those lines has two electrons in it and A would have more than eight electrons with those connected to it.

Page 13: More practice formula pages

Ex: What is the Lewis Structure for HCN?

Ans: There are 18 electrons needed, they have 10 electrons combined, therefore there are 8 electrons shared which means that there are 4 bonds. The formula would look like this:

H=C=N

Page 14: Lewis Structure 3

Ex: Draw the Lewis structures for carbon tetra-fluoride.

Ans: First you have to realize that that is CF4. Once you have done this, you can solve. Together they need 40 electrons. They have 20 electrons, this means that they share 20 electrons which comes out to 10 bonds. The formula would look like this:

.. ..

F F

/ /

C

/ /

F F

.. ..

Page 15: This is the final page of the journal and it is half of a page of practice problems.

Ex: Name the group of elements that X would belong to.

X .

Ans: X would belong to the Alkali metals group because it only has one valence electron and alkali metals only have one valence electron.

NEXT SCRIBER: JIMMY

11.8.10

Announcements:

-We picked up and taped in our calender for Unit 5

-As well as sheets 2-8

-This unit we will have 6 quizzes (and drop the lowest score if desired)

-Our first quiz will be tomorrow (Tuesday October 9, 2010)

Homework: Finish pages 2-8 (excluding page 3)

We started off by reviewing a little bit of covalent bonding (talking about where there is the least potential energy (when they are sharing electrons at a comfortable distance) and the most potential energy (when the atoms become too close so the protons of each nuclei repel each other)).

We took the rest of class to finish pages 2-8

Page 2: Questions about potential energy

-Ex: Does the potential energy increase/decrease as the atoms move closer?

Ans: Decrease as the atoms are sharing the electrons thus making their pull on them less.

Page 4: Naming Covalent Bonds Practice 1

-Ex: What is the name for the bond of CO?

Ans: Carbon Monoxide. Because there is only one carbon atom and it is the first atom named, the mono- is dropped leaving just carbon but because the second atom is oxygen and there is only one it uses the prefix mono and because the second atom should end in -ide, it becomes oxide creating Carbon Monoxide.

Page 5: Naming Covalent Bonds (2)

-Ex: CO. Ionic or Covalent?

Ans: Covalent (because it is between two non-metals) Carbon Monoxide

Page 6: Naming Covalent Bonds (3)

-Ex: Nitrogen Dioxide. Ionic or Covalent?

Ans: . NO2 (Because there is only one nitrogen it is simply nitrogen, and because there are two oxygens the prefix di- (indicating two) is placed in front of oxygen and the suffix -ide is placed at the end) and it is covalent (two non-metals)

Page 7: Naming Covalent Practice (3)

-Ex: PCl3

Ans: Phosphorous Trichloride (one phosphorous is simply phosphorous and because there are three Chlorines the prefix tri- (indicating three) is added as well as the suffix -ide)

Page 8: Naming Covalent Compounds (4)

-Ex: SiO2

Ans: Silicon Dioxide (again, one silicon is just silicon and because there are two oxygens a di- is placed in front and you get Silicon Dioxide)

10.4.10

Handouts:

·         Practice Conversions – due next Monday (only if asked by Mr. Pak but should be done anyway)

·         Periodic Table

Homework:

·         Two ChemThinks – due Wednesday

    

   - Atomic Structure

   - Isotope (take notes)

In Class:

·         We were given two pages to tape into our notebooks

-Electron Configuration 1 pg.6

-Electron Configuration 1 pg.7

·         We were given practice conversion sheets which if told that you needed to do them, they are due Monday.

·         Took notes from power point on Quantum Theory (see below for notes)

·         Went to the computer lab to work on the ChemThink’s.

Power Point Notes:

        Page 1-

              Quantum Theory

o   Where are the electrons?

o   Orbitals are predictions of electron location

Page 2-

       First Quantum # -n energy levels

o   1-7

o   Describes the energy

o   The larger, then more energy and usually further from the nucleus

Picture below is of electrons placed in definite orbitals (called shells) around the nucleus.

TESTS:

·        Test - October 8^th

·         Lab Test - October 11th

Oct 29, 2010

Polyatomic Ions
In class today we learned about naming and writing formulas for ionic compounds. The chart below shows some Polyatomic Ions.

• You have to treat these as One Thing.
  Ex) write the formula for elements:

Follow steps for naming and writing formulas for ionic compounds.

1)Find the name of each element

2)Write metal first

• If the first elements are in the transition column; Sn, Pb and D-block elements; then, you use roman numerals in the name of an ionic compound.
  Ex)
  

3) Write non-metal next

• For step 3, the non-metal ends with – ide.
  Ex) carbon→carbide



• When you have a polyatomic ion you write the given names of them.
  Ex) CaCO → calcium carbonate

Upcoming event!

We have Quizzes on Monday through Wednesday! Prepare for these quizzes!.

10.13.10

Metal Reactivity: Periodic Trends Lab

What we did today:

First We watched videos on how the Alkali Earth metals [Lithium, Sodium, Potassium, Rubidium, Cesium, and Francium(Francium excluded because it is illegal to obtain)] react with water. These were their reactions...

Li- Floats gives off H2 gas in reaction to water

Na- Similar reaction to water as Lithium ,but reacts more vigorously

K- Gives off flame with reaction to water

Rb- Similar to potassium ,but more violent

Cs- Cesium gives off a violent explosion with reaction to water

After the videos we were asked what trend that might be noticed as we go farther down the Alkali earth family column and the answer was they were more violent in reacting with water.

Next we were ask to describe the appearences of magnesium and aluminum.

Mg- Dull strip of metal

Al- Thin metal sheet

We were then asked what happens when they are ignited.

Mg- Sparkles with a blinding white light

Al- Shrivles

Todays Lab:

In todays lab we repeated what we saw previously in the day(combining the Alkali earth metals with water). Your data table should have similar if not the same information as the the data you collected from watching the video previous in the class period.

Post Lab Questions: (Answers)

1. Is a shiny metal more or less reactive? (Shiny metals are less reactive)

2. Which metal was most reactive in the air? (Calcium)

3. Rank the metals in order of most reactive with water to least reactive. (Ca,Al,Mg)

4. Which metal reacted to produce the most OH ions? (Calcium)

5. Rank the metals in order of most reactivity with water to least reactivity with HCl. N/A

6. Rank the four metals in this lab from the most reactivity to the least reactivity. (Ca,Al,Mg)

7. What can you conclude about the reactivity of metals as you move down a column or group? (Reacts more vigorously).

8. What can you conclude about the metals as you go across the periodic table? (More reactive)

9. N/A

Don't forget to look at your schedule to see what the homework is.

That concluded the day and the next scriber will be Brandon

PLEASE COMMENT

October 6, 2010

Electron Configuration
In class today we learned more about how to find the electron configuration of a nuetral atom. The point of electron configuration is to find the location of the electron.

Shapes of Orbitals
There are four different shapes of orbitals
1) S-one orientation-holds 2 electrons
2)P-three orientations-holds 6 electrons
3)D-five orientations-holds 10 electrons
4)F-seven orientations-holds 14 electrons


The S block always starts as 1S
The P block always starts with 2P
The D block always starts with 3D
The F block always starts with 4F

EXAMPLE 1: If the electron configuration of a neutral atom is 1s2 2s2 2p6 3s2 3p6 then....
a)How many electrons does it have?
18 electrons
(there are two ways in how to find this)

1. Add all of the second numbers together (2+2+6+2+6)
2. Look at the last electron configuration, which is 3p6, and find it on your periodic table.

b)How many protons does this atom have?
18 protons
(Since this is a neutral atom, the electrons and the protons are the same amount)

c)Write the symbol for this atom
Ar
(You can find this on your periodic table)

EXAMPLE 2: Lets say you need to write the electron configuration of Bi (Bismuth). You have to start with 1s2 and end with 6p3(which is where bismuth is located) The way to find write the in between atoms is to read the periodic table from left to right.
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p2.

Orbital Diagram

Each half arrow represents how many atoms are in that row.
ALWAYS PUT ONE HALF ARROW FIRST IN EACH BOX BEFORE PUTTING THE SECOND HALF ARROW IN IT.

Ionic Electron Configuration
To write the ionic electron configuration is same as usual. Except for example if they want you to write the electron configuration of O-2, then you have to find where O is, which is 2p4, and go forward 2 because you are gaining 2 more electrons, which is 2p6 and is the atom Ne (Neon)

IN CLASS
We did pages 6, 7 and some of 11 of electron configuration.

REMINDERS
Webassigns are due on Friday. Test is on Friday.

HOMEWORK
Page 8 of electron configuration.

October 1, 2010

ATOMIC STRUCTURE: In class on Friday we defined a few terms that have to do with atoms.

Proton- It has a positive charge and its location is in the nucleus (Remember Proton is Positive)

Neutron- Neutral, it has no charge. Its location is in the nucleus as well.

Electron- Located outside the nucleus. They have a negative charge



We also learned some stuff that has to do with the PERIODIC TABLE.

-The number located above the element's symbol is the atomic number. It represents the number of protons



-The number below the symbol is the atomic mass. That stands for the number of protons PLUS the number of neutrons.



*An atom will usually have the same number of protons and electrons. When those numbers are the same, it has no charge. The only way an atom can get a positive or negative charge is by losing or gaining electrons.

EXAMPLE:

Oxygen's atomic number is 8. Therefore it has 8 protons as well as 8 neutrons. If oxygen were to GAIN 2 electrons(making its total 10 electrons), then it would have a -2 ion(charge) because it has two more electrons than protons. On the other hand, if it were to LOSE two electrons (making its total electrons be 6), then it would have a +2 ion because it has two more protons.



ATOMIC MODELS:

We learned some stuff about orbitals and relative energy and other stuff with Bohr's model, but I did not quite undestand much of that thus, I would explain it poorly. Please be sure to ask Mr. Paek about that stuff.



FIREWORKS LAB:

The purpose was to observe the recations of 7 different salts when they were exposed to fire.

PRE LAB: When electrons drop down an energy level, they give off a specific amount of energy. The energy hits our eyes, excities our neurons, and then we see color.

QUESTION: What does the term "electrons becoming excited" mean?

ANSWER: Energy is added to the electrons so they jump energy levels.



Materials: 7 salts, sticks, water, Bunsen Burner.

Procedure: 1.First we wet the stick a bit in the water

2. Then we dipped it in the salt

3. We placed it over the Bunsen Burner (while it was lit) and observed the reaction

4. Then recorded it in our table



Results:

• Li+(Lithium) Gave off a hot pink color


• Na+(Sodium) Gave off a orange color that looked like fire


• K N O3 Gave off a dull green


• K Cl Gave off a dull purple


• Sr2+ (Strontium) Was red orange


• Cu(Copper) gave off a very dull green (almost white looking)

And Cu2+ was an emerald green

At the end we has three "mystery salts" and had to figure out which ones they were based on the results of the colors we got.

Postlab:

Why did each metal salt give off a different color? That's because they had different numbers of electrons and they each went to different energy levels.

NEXT SCRIBEPOST WILL BE: Zak