## Homework

- We will tend to only assign even exercises (the ones without answers).
- Odd questions are "optional' but highly recommended, since they will probably help you with the even exercises.
- All exercises are fair game for quiz questions.
- If you want to check if you are doing an even exercise right, you can try the odd one right before it. The previous odd one is (usually) similar, has an answer in the back, and a detailed explanation in the student solutions manual.

Set 1: Complete by September 17:

- Read: Chapter 1
- Types of matter: 2, 3 (it is one of the basic types of matter), 4
- Chemical Combination: 6, 7, 8, 10, 12
- Atomic Structure: 16, 20, 22
- Advanced (optional): 18 (set this up like an algebra problem), 24, 27, 28 (use algebra)
- Read: Chapter 1, Appendix 1, Appendix B1. You *must* be able to do calculations and conversions similar to these. If a,b,c,d of one problem all seem easy to you, move on to the next one.
- Math: Appendix A: #1, 3, 11, 17, 19
- Units: Appendix B: #1, 3, 9 (advanced, optional), 10, 11, 12

## darst recitations

- Introductions and stuff
- Everyone *must* be in the right recitation (at the very least, the recitation for the evening class)!
- Attendance is not strictly required except for: quizzes, the TAs will notice you are missing and communicate it with Dr. Beer, you won't learn as much.

- Measurements (using the extended example of my height)
- Physical quantity (eg, height)
- A number
- An unit
- meters or centimeters or feet and so on... don't let your grade do what the mars climate orbiter did.
- Assuming basic familiarity with the metric system. Summarize basic units, discuss them more as they come up.

- An uncertainty
- 185 cm or 185.000000001 or 184.999999999 cm ?
- Uncertainly is quantified by taking into account significant digits

- Scientific notation:
- Useful for very large or small numbers, can be used for any number.
- Speed of light: 2.99792458 e8 m/s
- Electron mass: 9.1093819 e-31 kg
- Examples of numbers with a small magnitude

- Significant Digits (vs "placeholder digits")
- Use my extended example to show how there is limited precision in addition.
- Multiplication: minimum number of significant digits in any multiplicand.
- Just what is a significant digit?
- 185 cm, 185.0 cm, 180 cm, 180. cm

- Formalize the rules:
- Everything between the first significant digit and last significant digit is significant.
- The first significant digit is the first non-zero digit.
- The last significant digit is the last non-zero digit OR the last digit after the decimal point
- A trailing decimal point makes ending zeros significant.

- Practicalities:
- Round at the end
- Rounding rules review. If it is exactly .500..., go to nearest even digit

- How much does this matter?
- You need to know that there are uncertainties
- For your own calculations, you can keep track of it however.
- When communicating with others, you need to be clear. (re: mars polar orbiter)

- NOTE: I want to rework all of this to use a shopping example and rounding money. There are many great examples here.

- Units
- Sort of discussed above with regards to the metric system.
- Units most often used: meter, centimeter, angstrom/nanometer ; second, nanosecond, picosecond, femtosecond; Mass: kilogram, gram ; temperature: K, C
- Conversions: look at the unit as something the number is multiplied by. Do some examples (to be decided)
- Examples (3.3ft = 1m):
- 100 m/s to miles/hour
- 12 feet x 8.5 feet to m^2

- Perspective on types of matter.
- You should have a vague idea about atoms
- You should have a vague idea about bonds
To decide what type of matter something is, think about where the atoms and bonds are. However, this isn't necessarily easy--- you haven't finished Gen

`Chem 1 yet !`- Go over some basic examples from problem #1

- Discussion of law of chemical combinations
- to be decided, but I don't think I'll have time to get to numerical problems.