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Topic 1. Measurement Observation and Inference. 1. Metric System: Based on the power of Ten. a. Prefixes i. Kilo- 1000 ii. Centi- 1/100, .01 iii. Milli- 1/1000, .001 2. Base Units a. Length- Meter (m) b. Volume- Liter (l) c. Mass- Gram (g) - PowerPoint PPT Presentation
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1. Metric System: Based on the power of Ten.
a. Prefixes
i. Kilo- 1000
ii. Centi- 1/100, .01
iii. Milli- 1/1000, .001
2. Base Units
a. Length- Meter (m)
b. Volume- Liter (l)
c. Mass- Gram (g)
Ex. 1.0 m= 100cm
1.0 mL= .001L
1kg= 1000g
3. Volume: The amount of space an object takes up. (cm3 or mL)
a. Volume of liquids
i. measured in a graduated cylinder
ii. unit (label) = milliliter (ml)
b. Volume of Regular Shaped Solids (i.e. rectangles/squares)
V = Length X Width X Height
H
LW
cmcm
cm
V = cm X cm X cm
Unit (label) = cm3 or
cubic centimeters
(Note: 1cm3 = 1 ml)
A
c. Volume of Irregular Solids
1) Water displacement in a graduated cylinder.
B
rock10 ml
25 ml
V= 25 ml – 10 ml = 15 ml
Therefore 15 ml OR 15 cm3
is the volume of the rock.
Unit (label) = ml or cm3.
4. Mass: The amount of matter an object contains.
(How much “stuff “is inside an object.)
a. Mass is measured with a Triple Beam Balance.
Unit (label) = grams
WHAT IS THE MASS ???????????
100’s
10’s
1’s
Mass = 79.4 grams
Electronic Balance… How do we use this???
Definition Instrument Unit
Length Distance b/w 2 points
Ruler Cm or m
Volume Amount of space an object takes up, size
Grad. Cyl.OrL x w x h
Mlorcm3
Mass Amount of matter in an object (# of molecules)
Scale g
5. Observation: a description using one or more of your senses.
Ex: The sky is blue.
The spoiled milk tastes sour.
The sandpaper feels rough.
6. Instrument: A man-made device that helps the senses observe better.
Ex: hearing aid thermometer
ruler triple beam balance
7. Measurement: an observation with a numerical value.
Ex: a) It is hot outside. = an observation
b) It is 80o F outside. = a measured observation
A. Measurements are made by comparing an object to a known standard.
ex: measuring instruments are known standards.
(rulers, balances, thermometers)
8. Classification: The process by which objects are put into groups based on similar or common properties.
Why do we classify?
It makes it easier to study. Organizes data.
Ex: Clouds: classified by shape and by altitudeRocks: classified by origin and by texture.
9. Inference: A thought process that provides a possible explanation for observations. (Educated Guess!)
Ex: observation: I see a round, smooth rock.
Inference: I think the rock was once in a river.
Predictions are inferences.
Ex: weather forecasts.
10. Percent Deviation (Error): The amount of error in a measurement as compared to the accepted value (actual answer).
% Error = Difference between measured and accepted value
Accepted ValueX 100
% Error = Difference between measured and accepted value
Accepted ValueX 100
Ex: student measurement = 127.5 g
accepted value = 125.0 g
% error = 127.5 g – 125.0 g
125.0 g X 100
= 2.0 %
11. Density: The amount of mass (matter) in a certain amount of volume (space).
OR
How close together the particles (atoms) are in a substance.
same volume
Less Dense More Dense
The closer the particles, the greater the density.
12. Density = Mass
Volume(grams per cm3)
2 cm
3 cm
7 cm
First find the volume:
V = L x W x H
V = 2cm x 3cm x 7cm
V = 42 cm3
Mass of the block = 168 g
Find the density of the block: D = m / v
D =168 g
42 cm3 = 4 g/cm3
Ex:
42 ml
60 ml
Mass of the stone = 54 g
Find the density of the stone:
D= m / v
Volume of stone = 60 ml – 42 ml = 18 ml OR 18 cm3
D= 54 g / 18 cm3
D= 3 g / cm3
13. The volume or shape of an object DOES NOT AFFECT IT’S DENSITY!!!!!!!!!!!!!!!!!!!!
Ex: Pebble of Rock A Block of Rock A
M = 12 g
V = 2 cm3
D = m / v = 12g / 2 cm3
D = 6 g/cm3
M = 3600 g
V = 10cm x 12cm x 5cm = 600cm3
D = m / v = 3600g / 600 cm3
D = 6 g/cm3
10cm
5 cm
12 cm
The volume or shape of an object does not affect it’s density!!!!!!!!!
Ex: An object has a density of 3 g/cm3
The object is cut into 10 pieces.
What is the density of each piece???
Answer: 3 g/cm3
Density problems…
A. An object has a mass of 48.0 grams and a volume of 60 cm3.
What is the density of the object?
D = m / v = 48g / 60cm3 = 0.8 g/cm3
B. The density of an object is found to be 4.2 g/cm3. What is the volume of this object if it’s mass is 126.4 g?
D = m / v 4.2 g/cm3 = 126.4 g
X
4.2 g/cm3 x X = 126.4 g
X =126.4 g
4.2 g /cm3
X = 30.1 cm3
C. An object has a density of 2.6 g/cm3 and a mass of 72.6 g. Another piece of the same object has a mass of 145.2 g. What is the density of this object???
D = 2.6 g/cm3
14.What can change the density of an object?
Three states of matter
• Solid, Liquid,Gas Most substances have their greatest density as a solid and their least density as a gas.
• When an object’s temperature increases, it’s density decreases.
• REASON: Heat causes the particles to speed up and spread apart
15. The Density of Water
Solid Liquid Gas0oC 100oC
MostDense
4oC
Water has it’s greatest density at 4oC
Solid water (ice) is less dense than liquid water.
Less dense materials float in more dense materials.
A
B
A is less dense than B.
16. Graphs
A. Graphs show the relationship between 2 variables.
B. Types of Graphs
1) Line Graphs
x x x
y y y
As x increases
y increases
As x increases
y decreases
As x increases
y stays the same
a) The steeper the line, the greater the rate (speed) of change shown by the graph.
2) Pie graphs.
E
A BC
D
The larger the section, the greater the value.
Which section is…
Largest
Smallest
D
B
3) Bar Graph
Y
X
The higher the bar the greater the value.
17. Given enough time, everything changes.
A. Some changes are fast and therefore are easier to observe or measure.
Ex: earthquakes, volcanic eruptions
B. Some changes are slow and therefore are harder to observe or measure.
Ex: erosion of a mountain, continental drift, growth of a tree
18. Cyclic changes: Changes that repeat at regular intervals.
Cyclic changes can be predicted
Ex: Seasons day and night
phases of the moon sunrise and sunset
TIME(X axis)
(Y a
xis)
CYCLIC CHANGE
One cycle
20. Non Cyclic (Random) Changes: Changes that occur at irregular intervals and therefore are difficult to predict.
Ex: earthquakes, volcanic eruptions, landslides, avalanches
TIME
NON-CYCLIC CHANGE
(X axis)
(Y a
xis)
No Patterns!!!
ENERGY1. Energy is the ability to do work.
2. All earth processes are the result of a transfer of energy.
3. Electromagnetic Energy
A. Electromagnetic energy is energy in the form of waves.
B. The Structure of Waves
A A
B B
CC
1) Wavelength: the distance between any 2 consecutive waves.
4. Types of Electromagnetic Energy
A. Gamma Rays
B. X-Rays
C. Ultraviolet
D. Visible Light
E. Infrared
F. Microwaves
G. Radio waves
*** The types of electromagnetic energy are different from each other by their
wavelength.
5. The Electromagnetic Spectrum
A. A chart that places the types of electromagnetic energy in their order of wavelength. (Reference Tables page 14).
Which form of electromagnetic energy has the longest wavelength?
Which form of electromagnetic energy has the longest wavelength?
Which form of electromagnetic energy has the longest wavelength? Radio waves
Which is shorter, UV or Microwaves?
Which is shorter, UV or Microwaves? Ultraviolet
B. The shorter the wavelength, the more dangerous the type of electromagnetic energy is to living things.
6. Speed of Electromagnetic Energy
A. ALL TYPES of electromagnetic energy travel at the speed of light.
186,000 miles/sec
300,000 kilometers/sec
7. Temperature and Electromagnetic Energy
A. The HOTTER the material, the more electromagnetic energy it gives off.
Ex: What gives off more electromagnetic energy, an object at 100oF or an object at 500oF?
Answer: 500oF
8. Methods of Energy Transfer
A. Conduction
1) In conduction, energy is transferred by the direct touching of particles.
2) Conduction is common in metals.Metal bar (circles are atoms)
Atoms touch atoms to move the heat
Ex: frying pan on a stove.
Ceiling
FloorWhat happens to the air above the flame (heat)?Heat causes the air to rise (less dense) carrying the heat with it.
Ex: winds
C. Radiation
1) In radiation, energy is transferred by electromagnetic waves.
2) No touching of particles needed.
No carrier (air or water) needed.
3) Radiation can occur directly across empty space.
Ex: The Sun’s energy reaching earth.
9. Direction of Energy Flow
A. RULE: Energy always moves away from the warmer area (source) and toward the cooler area (sink).
Ex:
Ice cube
water
70o inside
40o outside
10. Temperature
A. Temperature is the average speed of the particles of a substance.
1) The faster the particles, the higher the temperature.
B. Temperature is measured with a thermometer
In degrees.
11. Temperature Scales
A. Fahrenheit : U.S. Scale
B. Celsius : Metric Scale
C. Kelvin : (RT page 13)
Ex:
-16oF= ___________oC
14oC = ___________oF
40oC = ___________oK
58
-27
313
12. Heat
A. Heat is the total speed of the particles of a substance.
B. Heat is measured in Joules(calories).
13. Specific Heat
A. Specific heat is the amount of heat or joules needed to raise the temperature of 1 gram of a substance by 1oC.
B. The higher the specific heat the more heat it takes to warm it up.
Specific heat continued….
1) A high specific heat = harder to heat up.
2) A low specific heat = easier to heat up.
3) Reference Tables front page (top right).
Examples: 1) Which form of water will the temperature rise the quickest when heat is added to it? ______________
Reason: They both have a lower specific heat.
2) Which material takes the least heat to raise its temp?________
Reason: lowest specific heat
solid & gas
Lead
14. Change of State (Change of phase)
A. Latent Heat: The heat involved in a change of state.
SOLID LIQUID GAS
15. Examples of Phase Changes
A. Melting SOLID to a LIQUID
1)Latent heat is gained to melt a substance.
B. Freezing LIQUID to a SOLID
1) Latent heat is released to freeze a substance.
C. Evaporation LIQUID to a GAS
1)Latent heat is gained to evaporate a substance.
D. Condensation GAS to a LIQUID
1)Latent heat is released to condense a substance.
E. Properties of Water (RT front cover)
16. ADD HEAT (Gain)
TAKE AWAY HEAT (Release)
Melting
(80 cal/g)
Evaporation
(540 cal/g)
Condensation
(540 cal/g)
Freezing
(80 cal/g)
17. During a change of state the temperature of a substance STAYS THE SAME.
-60
-40
-20
0
20
40
60
80
100
120
HEAT
Tem
per
atu
re (
oC
)
HEAT
A= _______ D=___________ B-C_________________
B=_______ E=___________C-B__________________
C=_______ D-E_______________________
E-D_______________________
-50 (ice)
0 (ice)
0 (liquid)
100 (liquid)
100 (gas/steam)
No change in temp. (melting)
No change in temp. (freezing)
No change in temp. (evaporation)
No change in temp. (condensation)
A
B C
D E
18. Earth’s Energy Sources
A. Primary source: the Sun.
1) The sun’s energy drives all surface processes on Earth.
Ex: the weather
B. Secondary Source: Radioactive Decay
1) When radioactive elements inside the earth break down, heat is released.
2) This energy drives all interior processes
Ex: earthquakes, volcanoes, plate tectonics