This next set of problems deserves some comment. Problems concerning the exponential distance between two prefixes This makes it a prime target for teachers to test. Given either the name or the symbol of the prefix, give the other:Ī word to the wise: deca- (symbol = da) is a little used unit prefix. Here are only some possible problems (of many): Problems could give any one and ask for one or both of the others. There are three items - name, symbol, and size - that must be known. Notice anything? And, no, I did not copy them. For example, centigram means we are count in steps of one one-hundredth of a gram, μg means we count by millionths of a gram.įor another presentation of these prefixes, please go here. These skills will be necessary in order to correctly convert one metric unit to another.Ī metric prefix is a modifier on the root word and it tells us the unit of measure. Note for the future: you will need to determine which of two prefixes represents a bigger amount AND you will also need to determine the exponential "distance" between two prefixes. There is even someone selling an e-book for metric prefix flashcards. Here is a search for metric prefix flashcards. In order to properly convert from one metric unit to another, you must have the prefixes memorized. Whether these will catch on remains to be seen, but at least if you see such an unusual prefix you might want to be aware of this.A brief discussion of the basic metric units. This new system of binary prefixes has been endorsed by the International Electrotechnical Commission (IEC) for use in electrical technology. (Sounds like something you would feed the dog.) By this new system, 1024 bytes would be properly called a kibibyte or KiB. So, a new set of "binary prefixes", distinguished by "bi" in the name or "i" in the abbreviation, was introduced in 1998. But they are different numbers and sometimes it does matter. Now, in common usage it often does not matter whether the intent was 1000 bytes or 1024 bytes. That is 2 10 - a power of two very close to 1000. But in the computer world it often means 1024 bytes. What does it mean? It might seem to mean 1000 bytes, since kilo means 1000. You have probably heard words such as kilobyte, in the context of computers. "A picture is worth about 1.7 zmol of words." Radius of a chlorine atom in Cl 2 ~ 0.1 nm or 100 pmīond energy for one C=C double bond ~ 1 aJ World energy production per year, ~ 0.4 ZJġ light-year (distance light travels in one year) ~ 9.5 Pmġ light-second (distance light travels in one second) ~ 0.3 Gm prefixĪbbreviation (upper and lower case are important)Ī sense of scale (for some) Most are approximate.Įnergy given off by the sun in 1 second ~ 400 YJ To help you visualize the effect of these prefixes, there is a column "a sense of scale", which gives some examples of the magnitudes represented. In particular, the smaller prefixes such as nano, pico, femto, etc., are becoming increasingly common as analytical chemistry and biotechnology develop more sensitive methods. You will find prefixes from throughout the range as you read the scientific literature. There is no point of memorizing this, but it is nice to have a place to look them up. Our various textbooks and lab manuals contain longer lists of prefixes, but few if any contain a complete list. In introductory chemistry we use only a few of the most common metric prefixes, such as milli, centi, and kilo.
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