Periodic Properties Review

First in class we decided that we would take the chemistry lab test on Wednesday. Next we went over the Periodic Properties 2 worksheet (pages 12 and 13). On page twelve we went over the first five questions, they compared the first two columns of the periodic table (Alkali Metals and Alkaline Earth Metals). Remember: columns are the rows moving from top to bottom, they are sometimes also called groups. Mrs. Mandarino also noted that we must know what the term valence e- means; which is the outermost e-. (This word will be used on the test tomorrow).

Then we went over page thirteen; we firsts discussed electronegativity. Electronegativity is an atom's ability to attract a shared e-. Once a bond of valence electrons is made, both atoms will share the electrons in a shared e-.

Factors that will affect electronegativity:

• Amount of energy levels (atomic size); Less energy levels=valence electrons will be closer to nucleus=smaller atom will "hog" shared e- more.
• Shielding electrons; more shielding electrons=weaker pull from nucleus=atom will not "hog" shared e-.
• Number of protons in nucleus of atoms that are in the same period; greater pull from nucleus=smaller atom will "hog" shared e- more.

When going down-electronegativity will decrease.

Why?

-> valence e- are further from the nucleus=weaker pull=atom will not hog shared electron.

When going across-electronegativity will increase.

Why?

-> valence e- are closer to nucleus=stronger pull=atom will "hog" shared e-.

The Periodic Properties Review sheet is under the Unit 3 Periodicity Assignments. If you click on it, all the questions are answered and done for you. If you don't understand any of the questions, be sure to look back at all the worksheets we were given (pages 1-13) will help, also look through the fill in the blank worksheets we did in class. If you want extra practice or more to review print the Periodicity Practice Exam under the Unit 3 Periodicity Assignments.

*Remember: if you're having trouble always go back to atomic size.*

Also: The test is tomorrow and and the lab test was moved to Wednesday.

Effective Nuclear Charge, Atomic Size, and Ionization Energy

Today in class Mrs Mandarino first stamped our homework, which was #9 on the metal reactivity lab and pages 4-5 on effective nuclear charge. After that, we went over effective nuclear charge.

When protons increase --> greater pull on electrons, so its a smaller radius

We also learned how to find shielding electrons. The overall postivite charge that the electron gets is the effective nuclear charge (Z*). to find it, we can use a mathematical expression:

Z*=Z-S Z*- the effective nuclear charge
Z-the number of protons in the nucleus
S- the shielding electrons (electrons between the outer electron and nucleus)


Then we checked page 5. For 1, we had to find the number of shieling electrons. To do this, you cross out the highest energy level.

Example: Al 1s2 2s2 2p6 3s2 3p1
Cross out the third energy level because it is the highest and therefore the outer or valence electrons. Then you count the other electrons to get an answer of 10 sheidling electrons.

Part 2 was to find the effective nuclear charge. To do this, we had to use the mathematical expression.

Example: Al- Z*=13-10=3
13 is the number of protons in the element Al and 10 is the number of sheilding electrons. The answer 3 means that there are "3 protons pulling on the electrons"

Next, we learned about Atomic Size. We figured out that when you move down a column, the effective nuclear charge (Z*) stays the same. When you go across a row, (Z*) goes up. So the pull is stronger to the nucleus. More energy levels make the size of the atom larger, and a higher effective nuclear charge will make the size of the atom smaller.

Then we talked about Ionization Energy. This is the energy that can get the electron to completely leave the atom. So, the greater the force is that holds the electron in place, the more energy it will take to remove the electron.

When you move down a column, (Z*) stays the same, and the atomic size increases because there are more energy levels. So the ionization energy will decrease because the outer electrons are further from the nucleus. As you move across a row, ionization energy will increase because there is a stronger pull from the nucleus.

The homework for tonight was to do pages 10 and 11 and work on the webassigns!

Periodic Trends

Wednesday, October 20, 2010

Today we picked up pages 4,5,6, 7, Ionization Energy and Atomic Radius. The lab and pages 1,2, and 3 were then stamped. Next we worked on Part C of Metal Reactivity: Periodic Trends Lab. We then answered the questions on Metal Reactivity: Periodic Trends Lab, Periodic Table Practice 1(pg. 2), Periodic Table Practice 2 (pg. 3), Ionization Energy and Atomic Radius. Sheets and answers can be found on Moodle.


Homework was Webassings, #9 on Periodic Trends Lab and to read worksheet #4 and do worksheet #5.

Also Mole Day is Friday October 22 in the east gym at 6:02 a.m.

Participants will receive extra credit and don't forget to bring cans with.

Tuesday

Hello Class, I am sorry for creating this scribe post a day late but i shall quickly get to explaining what we did on tuesday. It was a very interesting class, i learned alot. We went to the science lab and logged on our computers, however our professor instructed a lesson first. She explained Periodic Trends which most of our class found extremely interesting, i learned that the atomic radius increases as you move down the periodic table. I did not know that before. We also learned that the atomic size decreases moving right to left on the table. After the lecture, we proceeded to our desktops on created graphs showing what we learned on Microsoft exel. Once we were finished we printed our graphs from the printer and took them home. It turned out to be a great class, filled with learning and i will cherish it for the remainder of the school year.

Thank You, Sincerely, Yours Truly Matt I

Metal, Non-metal, Metalloid

Monday, October 19, 2010

 Today in chemistry, our great teacher, Mrs. Mandarino stamped our alien homework that was completed a long while ago. Today we finished Metal, Nonmetal, and Meatalloid lab table. Then for homework we had to finish all the post lab questions that went along with the lab. After we finished up that lab we then started on our Periodic Trend Lab. We observed certain elements and how their reactions became more extreme the more we went down the list. Today was a fun day and instead of deciding who I want to scribe tomorrow in class I am going to pick now. Matt I. is going to be the scribe because he is going to ditch football and watch friday night lights.

Eric D.

Orbital Diagrams

Today we stamped and went over the homework on page 9. We also were assigned tape dispencer numbers. Next we took notes on orbital diagrams. We learned that orbitals are expressed by using a box and each orbital can hold a maximum of 2 electrons. 

                             Number of Electrons                Number of Orbital Boxes

s                                max. of 2e-                                         1

p                                max. of 6e-                                         3

d                                max. of 10e-                                       5

f                                 max of 14e-                                        7

• The up arorows in the boxes indicate electrons

• The up down arrows indicate e- with opposite spins

• Fill e- in the box individually first then double up

Homework was to finish page 10 and 11, work on Webassings and ChemThink. Test on Friday.


Kendall K

Electron Configuration

Today in class Mrs. Mandarino stamped page 5 that was for homework and later went over it in class.

Remember...

-No Charge = Same Number of Protons and electrons

-Negative Charge = More electrons than protons

-Positive Charge = Less Electrons than protons

After homework we started talking about the s, p, d, f orbitals.

- s orbitals: Can hold a max of 2e-

- p orbitals: Can hold a max of 6e-

- d orbitals: Can hold a max of 10e-

- f orbitals: Can hold a max of 14e-

Then we learned about...

Electron Configuration: "Adresses" or maps where we are most likely to find electrons.

- Example: 1s² 2s² 2p^{3 = N}

We used our periodic tables she gave us sometime ago. We labeled some parts of the periodic table with..

- 1s-7s

- 2p-6p

- 3d-6d

- 4p-6p

- 4f-5f

Ask Mrs. Mandarino or another student to show you how they labled it.

Today was pretty confusing. Suggest going to Mrs. Mandrino or the TLC for help if needed.

Today in class Mrs. Mandarino checked in our homework which was to complete the fireworks lab and pages 3 and 4. Then we went over the Rutherford simulation that we started on Wednesday after that we went over the fireworks lab. The fireworks lab was a lab where we wrote our observations on the fire that was created when we burned different metal ions. Next we went over pages 3 and 4 which were about atomic structure, the pages mentioned protons,electrons and neutrons and where they are located and whether their charge is positive or negative.They also included what a mass and a atomic number is,the atomic number is is the number of protons.At the end of class we looked at the power point and talked about the modern view of an atom and how its mainly empty space.We also looked at the different shapes of orbitals including s,p and d.

Homework: Pg. 5, read pg. 141-143, and webassign

Atomic Models Cont.

Friday, October 1st, 2010.


Today in class, we finished the class notes about atoms, and what Rutherford and Bohr did to help discover more, their experiments, and also the model of their atom. Afterwards, we did a lab called the fireworks lab, where we discovered what specific types of metal salts made what specific colors. After we all finished the lab, Mrs Mandarino gave us 3 mystery salts to solve. They related back to the salts we tested back in the lab.

The HW was to finish Chemthink, if not done already, and finish the questions for the fireworks lab :)


Alec W.