Grade 8 Unit 02: Chemical Formalas and Reactions (10 days)

TEKS

(5)  Matter and energy. The student knows that matter is composed of atoms and has chemical and physical properties. The student is expected to:

(D)  recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts;

(E)  investigate how evidence of chemical reactions indicate that new substances with different properties are formed; and

 

Assignments

1. Read 3.2 Ionic Bonds pp. 114-121
   1. 1. What is an ion? What kind of ions create ionic bonds?
   2. 2. In a chemical formula, what does a subscript mean?
2. Read 3.3 Covalent Bonds pp. 122-129
   1. 1. What happens to electrons in covalent bonds?
   2. 2. Describe single, double, and triple bonds.
   3. 3. Compare nonpolar and polar bonds.
3. Read 3.4 Observing Chemical Change pp. 130-137
   1. 1. What are the differences between physical and chemical changes?
   2. 2. What are some ways you can identify that a chemical change has happened?
   3. 3. What are the differences between exothermic and endothermic reactions?
4. Read 3.5 Describing Chemical Reactions pp. 138-150
   1. 1. What is the Law of Conservation of Mass? What does it have to do with the need to balance chemical equations?
   2. 2. Go to Chembalancer and PhET to practice balancing chemical equations I have no way of certainly grading whether you have done this, but I highly recommend it. When students are struggling with balancing equations, these resources are the best I have found to help them get it. Don't waste time, get started now.
   3. 3. Describe the three types of chemical reactions.

Review

Before you take the test on this unit, you should spend some time on the reveiw.