Basic Units•Length meters

•Mass kilograms

•Time seconds

•Temperature Kelvin

•Amount Chm Mole

•Current Ampere

•Luminous In Candela

MetricPrefixes

•Giga (G)

•Mega(M)

•Kilo(k) Nano(n)

•Milli(m)

•Micro() Centi(c)

MetricPrefixes

•(G) = 109

•(M) = 106

•(k) = 103 (n) = 10-9

•(m) = 10-3

•() = 10-6 (c) = 10-2

Accuracy•How close you are

to the real answer

Precision•How well one can repeat his or her work

•Repeatability

Uncertainty•All measurements have a degree of unreliability

•Usually in the last digit of a measurement

0

1

2

3

BuretteMeasurements

Eachmeasurementshould have2 decimals

Solve thecorrectreading for thevolumein theburette

0

1

2

3

BuretteMeasurements

Eachmeasurementshould have2 decimals

~ 1.36

the lastdecimalwill haveuncertainty

Significant Digits•Meaningful

digits in a number

Determining Significance

• All non-zero digits

• All zeros between non-zero numbers

• All trailing zeros if there is a decimal place

Multiplication Uncertainty

• The answer should have the same number of significant digits as the multiplier with the least number of SD

• Same for division

Addition Uncertainty• When adding, line up decimal

place & add

• The decimal places in the answer should = the least

• Same for subtraction

Scientific Notation•M x 10n

•M = 1.00 M < 10.00

•n = an integer

Conversion Factor• Ratio equal to one

• 12 inches/1 foot = 1

• Multiply one unit by a CF to obtain another unit w/o affecting magnitude

Convert:•2.50 cm to Mm

•4.2 ns to ms

•3.15 kg to g

Convert:4.35 kg/L to mg/L

2.31 mm/ns to cm/Ms

Calculate the volume in m3 occupied by 750 kg of gas with

1.50 g/L1 cm3 = 1 mL

Calculate the mass in kg of a board that has

dimensions of 250 mm x 4.0 x 104 m x 2.5 m and

had a density of 0.80 g/mL1 ml = 1 cm3

Calculate the density in g/mL of a 3.14 x 103 kg cylinder that 5.0 m long & has a diameter of 2.0 m.

How many nm willan object travel in

1/132 ks at720 miles per hour

1 inch = 2.54 cm1 mile = 5280 ft

Determine the length in miles of a light year

• Light year = distance light travels in one year

• c = 3.0 x 108 m/s

• 1 mile = 5280 ft

• 1 inch = 2.54 cm

Make the following conversions:

• 720 miles per hour to cm/ms

• 240 kg/m3 to g/nL

• 15 Mg to ng