4. Measuring Volume
We will be using graduated cylinders to
find the volume of liquids and other objects.
Read the measurement based on the bottom of the
meniscus or curve. When using a real cylinder, make
sure you are eye-level with the level of the water.
What is the volume of water in the cylinder? _____mL
What causes the meniscus?
A concave meniscus occurs when the molecules of the liquid
attract those of the container. The glass attracts the water on
the sides.
5. Measuring Liquid Volume
Imagescreatedathttp://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf
What is the volume of water in each cylinder?
Pay attention to the scales for each cylinder.
6. Measuring Solid Volume
10 cm
9 cm
8 cm
We can measure the volume of regular object
using the formula length x width x height.
_____ X _____ X _____ = _____
http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/e
n/syllabus/unit14/new/testingmain1.htm
We can measure the volume of
irregular object using water displacement.
Amount of H2O with object = ______
About of H2O without object = ______
Difference = Volume = ______
7. How hot? How cold?
direction of Heat Transfer
Celsius – 0 0
C Freezing Point of Water
100 0
C Boiling Point of Water
Kelvin = C° + 273
No degree signs are used
O Kelvin = -273.150
C
▪ coldest possible temperature
8. Length – size
meter (m)
Mass – amount of matter
Kilogram (kg) or gram (g)
Volume – space something takes up
Liter (l) or centimeters cubed (cm3
)
Temperature – amount of heat
Kelvin (K) = celsius + 273
9. Measure of how much matter is squeezed
into a given space
density = mass
volume
10. A block of wood and a block of steel have the
same volume
11. What happens to the density of an object if it
is cut into pieces?
Which has the greater density, a single
uranium atom or Earth?
12. coefficient x 10 raised to a power
Single gram of hydrogen
602,000,000,000,000,000,000,000 molecules =
6.02 x 1023
molecules
Mass of an atom of gold
0.000000000000000000000327 grams =
3.27 x 10-22
grams
13. 36,000
3.6 x 104
503,000,000
5.03 x 108
0.00076
7.6 x 10-4
14. The valid digits of a number
In measurement: includes all of the digits that
are known, plus a last digit that is estimated
15. Significant:
nonzero digits
final zeros after the decimal points
zeros between two other significant digits
Not significant
zeros used solely for spacing the decimal point are
not significant.
16. each have only two sig figs
0.0071 meter
0.42 meter
0.000099 meter
7.1 x 10-3
meter
4.2 x 10-1
meter
9.9 x 10-5
meter
18. If the digit immediately to the right of the last
significant digit is less than 5, it is dropped
5 or greater - last significant digit increased by 1
41.58 square meters 41.6 square meters
19. Round 65.145 meters to 4 sig figs
65.15m
Round 100.1°C to 1 sig fig
100°C
Round 154 cm to 2 sig figs
150
Round 0.000718 kilograms to 2 sig figs
0.00072
20. Counting
Example: 23 people in the classroom
▪ (Not 22.9 or 23.1) 23.00000000……………….
Exactly defined quantities
Example: 60 minutes = 1 hour
▪ 60.00000000……………………..
21. calculated answer cannot be too precise
not more precise than the least precise measurement
Multiplication and Division
same number of sig figs as the measurement with
the least number of sig figs
Addition and Subtraction
same number of decimal places as the measurement
with the least number of decimal places
22. Accuracy
How close a
measurement comes
to the actual value of
what is being
measured
Precision
How close a series of
measurements are
to one another
23. Difference between accepted value and
experimental value
error = experimental value – accepted value
% error = x 100%error
accepted value
24. % error = x 100%
99.1°C – 100.0°C x 100%
100.0°C
0.9°C x 100%
100.0°C
0.9%
error
accepted value
=
=
=
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