do now: read chapter 1.6. units matter!! part 1 - number part 2 - scale (unit) examples: 20 grams...
TRANSCRIPT
Do now: read chapter 1.6
Unit 1-3 SI units
How much does it cost?UNITS MATTER!!
The Nature of Measurement
Part 1 - numberPart 2 - scale (unit)
Examples: 20 grams6.63 x 10-34 seconds
A Measurement is a quantitative observation consisting of TWO parts
The Fundamental SI Units (le Système International, SI)
Physical Quantity Name Abbreviation
Mass kilogram kg
Length meter m
Time second s
Temperature Kelvin K
Electric Current Ampere A
Amount of Substance mole mol
Luminous I ntensity candela cd
The three major temperature scales.
5
TK = TC + 273.15
TC = TK – 273.15
Temperature scales Celsius scale
based on freezing and boiling points of water (0 oC – 100 oC)
Kelvin scale based on absolute zero (0 K) temperature at
which particles are at lowest possible energy NO negative numbers
K = oC + 273
oC = K – 273
Converting Between Celsius & Fahrenheit
TC = (TF – 32)X 5/9
TF = TC x 9/5 + 32You don’t need to memorize the conversion
between TC and TF
SI Prefixes Common to Chemistry
Prefix Unit Abbr. ExponentKilo k 103
Deci d 10-1
Centi c 10-2
Milli m 10-3
Micro 10-6
SI Prefixes1 T(base) = 1 000 000 000 000(base) = 1012 (base)
1 G(base) = 1 000 000 000 (base) = 109 (base)
1 M(base) = 1 000 000 (base) = 106 (base)
1 k(base) = 1 000 (base) = 103 (base)
1 h(base) = 100 (base) = 102 (base)
1 da(base) = 101 (base)
1 (base) = 1 (base)
1 d(base) = 10-1 (base)
1 c(base) = 10-2 (base)
1 m (base) = 10-3(base)
1 µ(base) = 1 000 000 (base) = 10-6(base)
1 n(base) = 1 000 000 000 (base) = 10-9(base)
1 p(base) = 1 000 000 000 000(base) = 10-12(base)
The
Great
Man
King
Henry
Died
By
Drinking
Chocolate
Milk
Monday
Night
Partying
Tera-
Giga-
Mega-
Kilo-
Hecto-
Deka-
Base
Deci-
Centi-
Milli-
Micro-
Nano-
Pico-
mega- M 106
deci- d 10-1
centi- c 10-2
milli- m 10-3
Prefix Symbol Factor
micro- 10-6
nano- n 10-9
kilo- k 103
BASE UNIT --- 100
giga- G 109
deka- da 101
hecto- h 102
tera- T 1012
Dec
imal
mo
ve le
ft
Dec
imal
mo
ve r
igh
tSI Prefix Conversions
pico- p 10-12
Prefix conversiongmL
10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Conversions between prefixes are merely a matter of moving a decimal point. The “base unit” means the you have a quantity (grams, meters, Liters, etc without a
prefix.
Metric ConversionsgmL
10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Example #1: Convert 18 liters to milliliters
18 L
1 2 3
18 liters = 18 000 milliliters
Metric ConversionsgmL
10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Example #2: Convert 450 milligrams to grams
123
450 mg450 mg = 0.450 g
Metric ConversionsgmL
10-1 10-2 10-3101102103
Baseunit
deci centi millidekahectokilo
Example #3: Convert 20 kilograms to milligrams
20 kg1 2 3 4 5 6
20 kg = 20 000 000 mg
Derived SI units
Volume= (length)3
SI unit of V: m3
Commonly used units of V:Liter(L)= dm3
Milliliter(ml)=cm3
a. cm to m
b. m3 to L
c. ns to s
d. kg to g
SI Prefix Conversions-concept check
SI Prefix Conversions-concept check
1) 20 cm = ______________ m
2) 0.032 L = ______________ mL
3) 45 m = ______________ m
HandoutDue next class.
Homework