1.8 NOTES – Metric Conversion

Why is it important to standardized measurment?

What’s the problem? Really? What?

Units of Measurement A. SI Units – International System; used in science throughout the world to provide continuity in research; 7 base units are used to derive every other unit; 1. Standard Base Units (SI base units). Give those for time, length, mass and volume: _sec, meter, kilogram, L____ gram is more commonly used when referring to balances.

Prefix Symbol Factor Scientific notation Example Giga G 1,000,000,000 109 *don’t use Mega M 1,000,000 106 Kilo k 1,000 103   Hecto h 100 102 Deka da 10 101 Base 1 Deci d 0.1 10-1 Centi c 0.01 10-2 Milli m 0.001 10-3 Micro μ 0.000 001 10-6 Nano n 0.000 000 001 10-9

Other measurements: b. Angstrom (Å) – prefix used for length only; 10-10; Swedish; c. Micron (μ) – used a lot in industry; micrometer

Prefixes are used to represent quantities that are larger or smaller than the base units

2. Conversions – 1) identify where you are starting 2) identify where you are ending 3) count the number of places the decimal would move AND direction 4) apply to your problem; each time you move, X10; common sense – if you move from big to small, the number should get larger b/c you need more and vice versa; must keep sig figs k h da _B_ d c m __ __ μ __ __ n Å

Sample Problems – (Reference bottom work area) k h da _B_ d c m __ __ μ __ __ n Å 2.5m  mm 24.0 cm  Ǻ 13 dL  kL 0.40km  m 0.0490 kg  cg 0.0018 μm  Ǻ