WI Monday Lecture
Chemistry
SI s steme International Units
subset of metric units
What Unit Symbol
Length meter m
Mass kilogram kg
temp Kelvin K
time seconds s
amount mole Mol
they have prefixes
prefix Symbol Multiple
giga O 10
mega 106
Kilo K 103
2
centi C 10
Milli M 10 3
micro M 10 6
a
nano N 10
12
pico p 10
femto f 10 is
8
at to a 10
Density expressed in compound units
d f
Joule SI unit ofenergy
1J lime
SignificantFigures SigFigs
Data reported with value and uncertainty
ex 765 4310.21
avoid the I byusing sigfigs
YOUHAVEUSEDTHERIGHTNUMBER IF ONLYTHELASTDIGITHAS UNCERTAINTY
ex 765.4 or 7.654.102 scientificnotation
This has 4 Sigfigs
Rulesfordetermining sigfigs in a measuredquantity
1 all nonzerodigitsandallzeroes betweennonzerodigits are significant
902L has 3 Sigfigs
2 zeros usedonly to position the decimal are not significant
Chemistry
SI s steme International Units
subset of metric units
What Unit Symbol
Length meter m
Mass kilogram kg
temp Kelvin K
time seconds s
amount mole Mol
they have prefixes
prefix Symbol Multiple
giga O 10
mega 106
Kilo K 103
2
centi C 10
Milli M 10 3
micro M 10 6
a
nano N 10
12
pico p 10
femto f 10 is
8
at to a 10
Density expressed in compound units
d f
Joule SI unit ofenergy
1J lime
SignificantFigures SigFigs
Data reported with value and uncertainty
ex 765 4310.21
avoid the I byusing sigfigs
YOUHAVEUSEDTHERIGHTNUMBER IF ONLYTHELASTDIGITHAS UNCERTAINTY
ex 765.4 or 7.654.102 scientificnotation
This has 4 Sigfigs
Rulesfordetermining sigfigs in a measuredquantity
1 all nonzerodigitsandallzeroes betweennonzerodigits are significant
902L has 3 Sigfigs
2 zeros usedonly to position the decimal are not significant
