Dave's ESL Cafe's Student Discussion Forums

[calcaneous]

First of all, I'd like to thank KazAV for answering my question yesterday. (I don't know how to post my comment below my writing.)

I'm currently working on some chemistry book. The first chapter is all
about reviewing high school chemistry. One of the main focuses of this chapter is something called "scientific notation". In this notation, a number is recorded in the form of A x 10^(+ or -integer). So, instead of writing down 3600, you write down 3.6 x 10^3. Anyway, according to the book, A should be a number between 1 and 10, and here's my question: Does this mean then A could be 1,2,3,4,5,6,7,8,9 or 10?

p.s: I'm pretty sure that A could be 1,2,3,4,5,6,7,8 or 9, but not 10. (since 10 is 1.0 x 10) If you are a Chemistry geek, please help me with this one, too.

[lotus]

Hi calcaneous,

You are right. For scientific notation, A x 10^(signed integer), A cannot be "10."

A should be x.yy where x is an integer between 0 and 10, and y can be any integer. The number of x's and y's depend on the number of significant digits in the number.

However, there is engineering notation, B x 10^(signed integer), where (.001<=B<=999). That's because the signed integer in the exponent must in increments of 3 (ie, -6, -3, 0, 3, 6). Examples:

.000001 = 1x10^(-6) or .001x10^(-3)
999,999 = 999.999x10^(3) or .999999x10^(6)

note: we do not generally use 10^(0) in engineering notation.


--lotus