Chem 106 Practical Everyday Chemistry Dr. Ron Rusay Diablo Valley College Spring 2003

What’s in the box? Take a look at one of the boxes coming around. Do not open it. Write down a description of what is in the box.

Chem 106’s Homepage

Science, Mathematics, Chemistry & the World Around You  What is science?…. What is chemistry?  VOCABULARY: Key Terms/ Communication  Comparisons and Conversions : Ratios, Percent, Density  Mathematics / Arithmetic: Powers of Ten, Scientific Notation  Measurement & Units: (metric)  Matter : Classification & Properties © Copyright R.J. Rusay

Observation: Perception Can more than one observation be correct?Can more than one observation be correct? What do you see?What do you see? Science relies on observation.

Science: Problem Solving Can you connect all of the dots with four straight lines without taking a pen or pencil from the surface?

Science: Problem Solving

Can there be more than one solution for the same problem? Of Course!

What’s in the box? Open the box. Describe what is in the box. The content of the boxes are different. How can you provide a single, “correct”, description of what’s in the box?

Ancient Science: The Greeks What is around us?

Science is driven by asking questions & making predictions. The Scientific Method is a way to develop answers.

Some Possible Steps in the Scientific Method  1. Observations ---- qualitative ---- quantitative  2. Formulating hypotheses ----possible explanation for the observation  3. Performing experiments ----gather new information to test whether the hypothesis is valid

Chemistry is the Study of Matter  Observed in all of its forms & behaviors.  Sub-categories Organic: carbon Inorganic: non-carbon Organometallic: Organic + Inorganic Analytical: What?, How much?, How pure? Biological / Biochemistry: living organisms Physical: energy, changes, rates Nuclear: the nucleus Environmental: interdisciplinary, eg. Oceanography © Copyright R.J. Rusay Can mean the study of anything and everything! Can matter be observed at all times?

Modern Science & Chemistry Would this motivate you to pursue a career in science/chemistry?Would this motivate you to pursue a career in science/chemistry? Why would this “excite” a scientist, and what does dating have to to with it?Why would this “excite” a scientist, and what does dating have to to with it?

How do we know how old things are ?… like sloth dung Dating! Radiocarbon dating that is. It allows determining the age of biological artifacts like dung up to about 40,000 years old. This method provides an direct measurement of age. How do we determine our own age?How do we determine our own age? Can this work for anyone or any animal that ever lived?Can this work for anyone or any animal that ever lived?

Match the years in the second column with choices from the first column B C E I F L K G D A H J

Types of Basic Measurements MASS (weight) LENGTH VOLUME (occupied space) TEMPERATURE TIME Qualitative vs. Quantitative Eg. Qualitative: Old (dung) vs. Young (you?) Quantitative: 38,000 year old (dung) vs. a 19 year old (you?) © Copyright R.J. Rusay

What is the length of the rod? Different measurement tools give different numbers: Which ruler is better? Did the Hubble space telescope use English or metric units in its construction? …..navigating the Mars Climate Orbiter?

Volume (Liquid Measurement Tools)

Relative Temperature Scales

Temperature

Representations of Measurements: An example of a relative comparison using length to represent time TIME: 38,000 year old (dung) vs. 20 year old student LENGTH: Use lines to represent the respective ages that can be easily drawn on the classroom’s blackboard. Let 1 inch equal some period of time: 1 yr, 5 yr, 10yr, 100yr, 1000yr. (Select an appropriate one.) 38,000 year old (dung) vs. 20 year old student © Copyright R.J. Rusay

Representations of Measurements An example of a relative comparison using length to represent time TIME: LENGTH; 38,000 year old (dung) vs. 20 year old student 1 in= 1 yr: dung = 38,000 in (> 1/2 mile) - student = 20 in 1 in= 5 yr: dung = 7,600 in (> 2 football fields) - student = 4 in 1 in= 10 yr: dung = 3,800 in (> 100 yds) - student = 2 in 1 in= 100 yr: dung = 380 in ( 31.6 feet) - student = 0.2 in 1 in= 1000 yr: dung = 38 in ( 3.16 feet) - student = 0.02 in © Copyright R.J. Rusay

Representations of Measurements An example of a relative comparison using length to represent time TIME: LENGTH; 38,000 year old (dung) vs. 20 year old student 1 in= 1 yr: dung = 38,000 in (> 1/2 mile) - student = 20 in 1 in= 5 yr: dung = 7,600 in (> 2 football fields) - student = 4 in 1 in= 10 yr: dung = 3,800 in (> 100 yds) - student = 2 in 1 in= 100 yr: dung = 380 in ( 31.6 feet) - student = 0.2 in 1 in= 1000 yr: dung = 38 in ( 3.16 feet) - student = 0.02 in © Copyright R.J. Rusay

Chemistry in your car: Airbags Count how many words are new to you. A) ZeroB) 1-5C) 6-10D) >10