Monday, February 21

Today I handed back the tests students took last week on bonding. Corrections are due by Friday!

Today we started balancing chemical equations. This can be very challenging and is very much like math. Tomorrow we will continue to work on this concept and there will be a homework assignment for reinforcement. If students need additional practice, here are some websites that offer some help:

http://www.files.chem.vt.edu/RVGS/ACT/notes/Types_of_Equations.html#Top
http://www.files.chem.vt.edu/RVGS/ACT/notes/scripts/bal_eq1.html (this program requires you to put a number in for all response areas. Instead of leaving a space blank if it has one molecule, put in the 1 !!
http://sciencespot.net/Pages/classchem.html#Anchor8 (go to "balancing act" section about half way down.

for those who are ready for the next step, you can go to this link:
http://www.glencoe.com/sites/common_assets/science/virtual_labs/PS16/PS16.html

• this site also asks you to calculate the molecular weight of the reactants and products to check for a balance of your equation.
  
• Just click on the "elements on" button to see each element from the periodic table. Use the atomic mass multiplied by each atom in your equation.
• Example: for water, H2O, each hydrogen has an atomic mass unit (amu) of 1 and the oxygen is 16 amus. Therefore, 2 (one for each hydrogen) + 16 = 18 amus for each molecule of H2O.
  

Test on Bonding

Today, students finished reading the section in the book about covalent bonding and metallic bonding. They also completed a guided reading handout as they read. We have gone over them in class with all but my 4th period, so they should be complete and can be attached to page 107 in their notebooks.

On page 106, should be the essential question: How are covalent bonds formed? Describe the properties of metals and how metallic bonds form. They should also do a Venn diagram that compares ionic bonding and covalent bonding. Items that are characteristic of covalent bonds should go in the green circle. Items that are characteristic of ionic bonding should go in the black circle. (Their diagrams do not have to be color coded) Items that are characteristic of both should be written where the two circles overlap. This can be done on a separate piece of paper then attached to p. 106 or it can be drawn directly into the notebook.

As the title of this entry indicates, we will be having a test on bonding next week. Most likely on Wednesday, but I am still working out the details of next week. This test will cover notebook p. 100-103, 106 and 107. I passed out a "vocabulary activity" today to help them begin to review. I am not requiring this as homework, it is a study guide of the important terms we have encountered this Chapter. I will have the answers posted on my bulletin board on Monday. Also, it is Chapter 9 if you would like your student to review the book on-line.

Have a great weekend!

Tonight's homework

Today in class we discussed last weeks lab and the questions that went along with it. We also started working on a practice sheet to help students recognize the atomic number tells us the number of electrons and protons in an atom. The number of valence electrons is indicated by the group (sometimes called family) number by looking at the last digit of the group number (ie. group 13 has 3 valence electrons. This method only works for groups 1, 2, and 13-18!!!! These valence electrons are responsible for bonding.

Also, on the opposite side (Titled: "Reinforcement--Is It an Ion?") of the homework sheet, is an activity to help students calculate if an atom is a neutral atom or an ion. This assignment is due tomorrow, February 9.

Last week and today!

On Monday of last week, we began learning about valence electrons and chemical bonding. On Tuesday, we had a quiz, and students began reading about ionic bonds. I realized that students were having difficulty with a concept, so I retaught a different method of counting valence electrons and drawing a diagram of the electrons in an atom on Wednesday and did not count that part of the quiz. Also on Wednesday, students had time to complete the reading and guided reading worksheet on ionic bonds. On Thursday, we did a lab that demonstrated a chemical reaction. They put there data table on p. 104-105 of their notebooks.

This week, we have started off by going through what we read on ionic bonds, and we checked our guided reading sheets and glued them into our notebooks on p. 103. Homework that is due Tuesday are 4 questions about the lab. I put them on a half sheet of paper that we glued/taped into our notebooks on p. 104 or 105.

Just in case, I will post the questions on my school web page. Tomorrow we will be doing some reinforcement to help students further understand ions and ionic bonding. I have included a summary from the book to the top left that summarizes what we discussed in class today. Let me know if I need to make it bigger. I will also include it as a file on the web page.