# 03-Units _ Math

```Basic Units
•Length meters
•Mass
kilograms
•Time
seconds
•Temperature Kelvin
•Amount Chm Mole
•Current
Ampere
•Luminous In Candela
•Giga (G)
•Mega(M)
•Kilo(k)
•Milli(m)
•Micro(m)
Metric
Prefixes
Nano(n)
Centi(c)
•(G) =
6
•(M) = 10
3
•(k) = 10
-3
•(m) = 10
-6
•(m) = 10
9
10
Metric
Prefixes
(n) =
-9
10
(c) =
-2
10
Accuracy
•How close you
are to the real
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
Burette
Measurements
Each
measurement
should have
2 decimals
0
1
2
3
Solve the
correct
for the
volume
in the
burette
Burette
Measurements
Each
measurement
should have
2 decimals
~ 1.36
0
the last
1 decimal
will have
2 uncertainty
3
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
• When adding, line up decimal
• The decimal places in the
• Same for subtraction
Scientific Notation
•M x
•M = 1.00  M &lt; 10.00
•n = an integer
n
10
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 mg
Convert:
4.35 kg/L to mg/mL
2.31 mm/ns to cm/Ms
Calculate the volume
3
in m occupied by
750 kg of gas with
1.50 g/L
3
1 cm = 1 mL
Calculate the mass in kg of
a board that has
dimensions of 250 mm x
4
4.0 x 10 mm x 2.5 m and
had a density of 0.80 g/mL
3
1 ml = 1 cm
Calculate the density
in g/mL of a 3.14 x
3
10 kg cylinder that
5.0 m long &amp; has a
diameter of 2.0 m.
How many nm will
an object travel in
1/132 ks at
720 miles per hour
1 inch = 2.54 cm
1 mile = 5280 ft
Determine the length
in miles of a light year
• Light year = distance light
travels in one year
8
• c = 3.0 x 10 m/s
• 1 mile = 5280 ft
• 1 inch = 2.54 cm
Make the following
conversions:
• 720 miles per hour to cm/ms
3
• 240 kg/m to mg/nL
• 15 Mg to ng
```