LARN 025 C7D1
Start the following in class:
1. The required journal focus questions, J25, for today are:
Suppose you measured the length of a rectangular piece of aluminum foil as 180.7 mm.
a. Which digits resulting from measurement decisions in the laboratory are significant?
180.7 mm = 0.1807 m =1.807 x 1010 nm = 1 8 070 000 000 nm = 0.000 180 7 km
b. Which zeros resulting from expressing a measurement in terms of a very large or very small unit of measurement are significant?
2. a. Go to https://socratic.org/chemistry to research the topics brought up in section 3.1 of your text, OR use the PQ5R or SQ5R method to prepare a study guide for section 3.2 of your chemistry text on The International System of Units, SI. Read section 3.2 in your chemistry text, pages 73 through 79, and as you do, create a study guide using the SQ5R or PQ5R method explained in class and on the distributed handout packet. Or, if it will save you time, write a question for the section, read the section for the main idea and write a summary paragraph when you are done reading. You may record vocabulary entries in the body of your study guide, or you may check them off on the chapter 3 vocabulary list as you think about the meanings of the terms and add any notations to the vocabulary list for clarifications sake.
b. For your convenience, a summary of the SI is given in a in SI Information. Go to https://physics.nist.gov/cuu/Units/prefixes.html to find out the name, symbol, and meaning of each SI prefix and to review the name, symbol, and meaning of each original metric prefix. Make sure you study the SI prefixes and their meanings until you are able to readily explain the meaning of each listed SI prefix as a numerical multiplier. The prefixes that we will come across most frequently in our chemistry course probably are Tera, Giga, Mega, kilo, deci, centi, milli, micro, nano, pico, and femto. Note that SI prefixes denoting multipliers larger than 10³ all end in the letter a and SI prefixes denoting multipliers smaller than 10– 3 all end in the letter o.
Recommended for those who have time left in their 45 minute study period, but not required of all:
1. Do some formative assessment problems to inform you about the degree of your comprehension and understanding. Assessment questions printed at the end of the section that you have just read. Reflect on your answers. Make sure that you have understood the major points in the section that you have just read.
- In your Learning Log use blue or black ink and place your hand in number in a circle followed by your name in the upper right white space of a piece of three holed composition paper that hasn’t been written on.
- Place the page reference for the problems to be considered to the left of the red marginal line on the first blue line. Centered on the first blue line,write a descriptive title for the learning activity such as Section [chapter #.section#] Responses.
- Before you write your response to each question or problem listed below, write its designation to the left of the red marginal line as listed below, followed by your response in ink to the right of the marginal line.
- You need to make sure you understand those questions that you find challenging, so you only need to record your responses to questions that are challenging you, so that you can later review what you are learning. If all problems seem easy to you, record the response to the one that was least easy for you in your opinion.
- Study Sample Problem 3.4 on page 78 and then show your work for practice problems I3-16 and I3-17.
- In the Section Assessment 3.2 on page 79, read, analyze, and show your work for practice problems I3-18 through I3-27.
- Selected suggested responses to some of the formative assessment questions are found in Appendix E [pages R82 through R106 at the back of the text]. After you are finished, check page R83 of the text and check each of those problems that you can by writing in either a check mark (√) or a correction in green ink as we do in class.
- Some questions do not have a suggested response given. For those questions, circle the numbers of the questions in the margins of your notebook paper and check your response with that of your classmates when you come to class.
2. Click on Linear Measurement to practice making measurements of length by using he online ruler to the maximum precision attainable. Ordinarily the scale on a measuring instrument is readable to one-tenth of smallest division marked on it.
- On a clean page in your Learning Log, place your hand in number and name in the upper right white space and record the digits and units for the length for nine of the objects.
- On the paper to the left of the red marginal line,starting on the fourth line from the top of the paper, number the next nine blue lines sequentially starting with the number 1 followed by a period, and so on to number 9.
- There are 16 objects that could be measured on this web site, but you only need to measure the length of nine of them. The eight small objects for you to measure are the SD memory card, key, cell phone, pencil sharpener, glue container, quarter, dime, microwave, and the one large object is a car.
- Press the Help key at the lower right and the Config[uration] key to receive help and to configure the measuring instruments.
- List the objects, one per line followed by a colon after which you write the correct digits and SI unit for the length each object.