Measurement and Units
Module 1 is all about the math foundations of chemistry. The skills presented in this module will be used in nearly every module from here on out. Not only in this text, the concepts such as measurement (how many digits can you claim from a particular measurement device), significant digits, scientific notation, and the factor-label method (unit conversions) will be critical for many years worth of science to come in high school and college. It will be very important to get a good grip on them. These skills are so important that we will take a leisurely three weeks instead of the usual two weeks to cover the material to give all students plenty of time to nail the topics down.
Lecture 1: Measurement and Uncertainty
In science, accuracy and precision are not the same thing. Accuracy is how close a measuring device is to standard. Will your kitchen scale actually show an object to measure 1 gram when it actually is one gram?
Precision is a term that concentrates more on how consistent a measurement device is to give consistent readings. You can spin the little adjustment wheel on your bathroom scale so that it shows you weigh 70 lbs when you really weigh 140 lbs (would that be a great diet technique? hehe). Your scale may be very precise in giving a measurement of 70 lbs over and over again, but tha wouldn't be an accurate weight. Get the idea?
Precision is a term that concentrates more on how consistent a measurement device is to give consistent readings. You can spin the little adjustment wheel on your bathroom scale so that it shows you weigh 70 lbs when you really weigh 140 lbs (would that be a great diet technique? hehe). Your scale may be very precise in giving a measurement of 70 lbs over and over again, but tha wouldn't be an accurate weight. Get the idea?
Lecture 2: Metric and SI Units
High school is when students begin to leave the world of English system measurement behind. Now everything is centimeters, liters, grams, and degrees Celsius. In this lecture, the students will learn some handy benchmarks to make the transition a little easier. We will also get a chance to practice how to use the metric prefix system.
In the image to the right, you can see a few benchmarks. A gram is about the mass of a fly. One kilogram is about the mass of two-and-a-half packs of butter. One centimeter is about the width of your index fingernail. Remembering these personal benchmarks can help you get a feel for what the base units actually are in everyday experience in the metric system.
In the image to the right, you can see a few benchmarks. A gram is about the mass of a fly. One kilogram is about the mass of two-and-a-half packs of butter. One centimeter is about the width of your index fingernail. Remembering these personal benchmarks can help you get a feel for what the base units actually are in everyday experience in the metric system.
Lecture 3: Significant Digits ...
Significant digits and rounding rules will be very critical to learn because all of the math in all the remaining modules of chemistry and on to physics will rely on a good understanding of them. The idea behind significant digits (also called significant figures) is to not claim any more accuracy in measurements or calculations than the measuring device really can give you. For instance, you might do some multiplication on your calculator and come up with a number with a whole screen full of numbers after the decimal point. This gives the impression that the lab measuring device must have been incredibly accurate. To communicate that just a simple dime store ruler was used, in the final calculation you would select the numbers you calculator spits out that has the number of digits to show it to be less accurate than your calculator thinks it is.
... and Rounding
Here a catchy tune to teach you about rounding ...
Lecture 4: Factor Label Method
The factor Label Method, or dimensional analysis method, is a great mathematical tool for converting one unit of measure to another unit of measure. Once you get the hang of it, you will love how it actually works to verify that you set it up right when you use and cancel the units.
This handy mathematical tool will come in handy in nearly every module in the rest of the text. The problems that the students will be working with won't always be given in the correct units, so they will learn to be alert to when they need to convert the units into a useful base unit.
This handy mathematical tool will come in handy in nearly every module in the rest of the text. The problems that the students will be working with won't always be given in the correct units, so they will learn to be alert to when they need to convert the units into a useful base unit.
Lecture 5: Density
The topic of density is in this module, but here at the site I have the content for it listed under its own sub menu in the navigation bar up top - click here for a fast link to it. It is a wonderful topic with so much to explore. Officially, we will only be touching on the topic deeply enough to give us a practical application of what we have been learning about for measurement, but if you want to go deeper into density, just look it up in the navigation menu and see all the nifty experiments you can do to learn it much deeper than mere measurement practice.
The Importance of a Scientific Calculator
This course will likely be the very first course in which a calculator will become an important tool and the student will need to get in the habit of having one at the ready during class time. Your student will have to have a calculator capable of doing scientific notation. Take a look to see if there is an exp or EE key on the keys anywhere. If there isn’t a key like this, then I recommend getting a scientific calculator. There will be many high school and college courses in their future that will need one. Iit is an investment that will be put to use over time.
You don’t have one and cannot buy one right now? No problem. There is one right on your computer and one that you can link to in the course page in the top block. I will be showing students how to do scientific notation on their calculators, in the course, and on the one on the Windows and Mac computers. Even if you have a hand-held calculator, it is nice to know that if it turns up missing one day there is a calculator on the computer and on the course page to use when needed.
You don’t have one and cannot buy one right now? No problem. There is one right on your computer and one that you can link to in the course page in the top block. I will be showing students how to do scientific notation on their calculators, in the course, and on the one on the Windows and Mac computers. Even if you have a hand-held calculator, it is nice to know that if it turns up missing one day there is a calculator on the computer and on the course page to use when needed.