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

9.30.10

Anouncements:

• If Mr. Paek is not in class he has asked for us to be nice to the sub
• Tomorrow we will be in the computer lab or we may do a fireworks lab
• There will be a quiz sometime next week

Homework:

• Page 118 #14
• Read pages 106-109

In class:

• Got 6 pages to tape into notebook (to be taped as shown)

- 2 Atomic Model pages

- 2 Atomic Structure pages

- 2 Rutherford Simulation lab pages

• Completed Rutherford Simulation lab with a partner

- Put black carbon paper upside down on top of a white sheet of paper with 6 circles with a small square in the middle of each one

- Take small yellow ball and bounce it on the carbon paper around 100 times

- Answer questions using calculator

• As a class we answered questions 1-8

- Do not use ruler - only a calculator - for these questions

• Talked about what the lab represented relative to Rutherford's experiment with the foil

- White paper: gold foil

- Circles: atom

- Marble: (+) random particles

- Squares: nucleus

• Finished questions 1-4 on back page of lab in class

Exam: 10/8

Lab Exam: 10/11

The next scriber will be Andrea.

9.21.10

Homework Read pgs. 106-109 and complete pg. 106 #14

Today in Class

Today in class, we worked on and finished up the Atomic Scientists worksheet. We will be able to use this on the upcoming quiz, so it is important to take good notes on scientists and their contributions to the development of the atomic theory.

We were told by Mr. Paek that are goggles needed to be in Zipblock bags incase of spread of pink eye or infection. If anyone has not done so, make sure to do it tomorrow in class.

Next, we took notes on a powerpoint that was all about the four atomic scientists. The first scientist was Dalton, who in the early 1800s contributed the solid sphere model. He concluded that each element is made of atoms, atoms of one element are identical, compounds are made from different elements in whole number ratios, and that chemical reactions involve the rearrangement of atoms. The next scientist was J.J Thomson who concluded in 1897 that negative atoms must have a negative charge, and negative is negative, with overall neutrality, then must also have a positive change. He found this out by holding a magnet to sides of a tube and noticed a bend in the light. The positive side attracted the beam and the negative side repelled the beam. Another scientist was Ernest Rutherford, who in 1911 shot an alpha particle (positive charge)through gold foil. Most all went through some had deflected. He found all atoms have a tiny positive center called the Nucleus. The last scientist was Niel Bohr who in 1914 found that electrons "orbit" around. Electrons move around the nucleus in a cloud.

Pictured below are each scientist's Atomic Model

Bottom left to right:Bohr's atom, Current orbit atom

Top left to right: Dalton's atom, Thomson's atom, Rutherford's atom

Upcoming test-October 8th, lab test-October 11th

NEXT SCRIBER ..MAHAK!

9.28.10

Homework:
Read pages 101-106 in the Chemistry Text Book. There is no question today.

Class Today:
The lab today was called the "Black Box Lab." You went around the lab stations trying to find out the blockade in the black circle container. It was filled with a bead and you had to figure out the blockade without opening the box. After you felt confident in your answer you had to write the numbger of the black box down and then draw what you thought the blockade was. It was extremely confusing and difficult, often leading to extremely odd answeres from some of the class members.

This however was an extremely amazing metaphor for scientists Dalton, Rutherford, Bohr and Thomson whom all tried to decide what the shape of an atom was. They didn't have any microscopes that could see anything that tiny. Hence, the "Black Box Lab."

Reminder:
There is going to be a quiz on all four of these scientists soon. Do the worksheet assigned today that you can use on the quiz. Take notes from the four sheets that Mr. Paek gave us and you'll be good to go.

Also, the test is on Oct. 8th and the Lab test is on Oct. 11th.

Plus, if you want to retake your Lab Test, then tell Mr. Paek what day and period you're coming in.

The next scriber will be Kaylee.