Chemistry 2

Scientific Notation/Units

  1. Scientific Notation
    1. Used when expressing very large or very small numbers.
    2. Eliminates ambiguous numbers of significant digits (more on this later)
    3. Is written in the form such that the first number is greater than or equal to 1 and less than 10, and is multiplied by some factor of 10.
      • 1.04 x 10^6 would be equal to 1,040,000
      • 3.650 x 10^ -14 would be equal to 0.00000000000003650
      • you will see different forms for scientific notation but all of the following are equivalent
        • 2.4 x = 2.4 x 10^6 = 2.4 x 10+6 = 2.4 e+6
    1. Try this now on your calculator to see which form it uses to display scientific notation. You can see this by repeatedly multiplying or dividing some number by a very large number.
    2. To get some practice with converting numbers between "ordinary" decimal notation and scientific notation go to:
      http://janus.astro.umd.edu/astro/scinote/
  2. Units
    1. Prefixes are commonly used in expressing a unit of measurement.
    Prefix
    Symbol
    		Factor Meaning Prefix
    Symbol
    		Factor Meaning
    yotta
    Y
    		1024 septillion yocto
    y
    		10-24 septillionth
    zetta
    Z
    		1021 sextilltion zepto
    z
    		10-21 sextillionth
    exa
    E
    		1018 quintillion atto
    a
    		10-18 quintillionth
    peta
    P
    		1015 quadrillion femto
    f
    		10-15 quadrillionth
    tera
    T
    		1012 trillion pico
    p
    		10-12 trillionth
    giga
    G
    		109 billion nano
    n
    		10-9 billionth
    mega
    M
    		106 million micro
    µ
    		10-6 millionth
    kilo
    k
    		103 thousand milli
    m
    		10-3 thousandth
    hecto
    h
    		102 hundred centi
    c
    		10-2 hundredth
    deca
    da
    		101 ten deci
    d
    		10-1 tenth

    You should memorize the ones in bold. We will use them often.
    Go to: http://www.wordwizz.com/pages/10exp27.htm or http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/ to get a sense of the difference between these powers of ten.

    1. We will be using metric units for all our measurements in this class so you should memorize the following:
      • length will be measured in meters (m) or centimeters (cm)
      • volume in centimeters (cm^3), milliliters (mL), or liters (L)
      • mass in grams (g) or kilograms (kg) - Note: at no time will we be measuring the weight of any substance in this class, only its mass.