Download Laboratory Performance Test - Mr. Volpe`s Earth Science Emporium

Laboratory Performance Test
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Evaluate lab skills developed throughout the year
Must be taken before the written exam
Accounts for 15% of overall regents exam grade
Consists of three stations
Allotted 9 minutes to complete the tasks
associated with each station
Minerals
• Mineral: naturally occurring substance with a
unique crystalline structure and chemical
composition
• Identification based on:
– Luster: metallic or non-metallic
– Hardness: resistance to being scratched; measured on
the Mohs scale
– Cleavage or fracture: how the mineral breaks
– Streak: colored powder, if any, left behind after
mineral is rubbed on a surface
– Acid test: bubbles result if calcium carbonate is present
Streak: is the color of the mineral
in powdered form
How to test for streak:
Rub the mineral on an unglazed white
or black ceramic tile
Luster the way a mineral shines
in reflected light
The mineral on the left has a
metallic luster, the one on the
right, a nonmetallic luster
The Main Physical Properties
Used to Identify Minerals
Luster
how light reflects off a mineral
metallic
non-metallic
looks like a
metal
looks earthy, waxy,
greasy
C. The Main Physical Properties
Used to Identify Minerals
Breakage
How a mineral breaks apart
a. Cleavage: The mineral breaks in
a predictable pattern. It is a clean
break which leaves smooth sides.
b. Fracture: the mineral breaks randomly
Hardness
resistance to being scratched
a. How to test: scratch mineral on glass
If the mineral does not
scratch glass its soft
If the mineral does
scratch glass its hard
LUSTER- Now you try…
NON-METALLIC
LUSTER- Now you try…
NON-METALLIC
LUSTER- Now you try…
METALLIC
CLEAVAGE OR FRACTURE
CLEAVAGE
CLEAVAGE OR FRACTURE
CLEAVAGE
CLEAVAGE OR FRACTURE
FRACTURE
Igneous Rocks
• Igneous rock: formed from cooled and hardened
magma (intrusive) or lava (extrusive)
• Intrusive: formed inside earth
– coarse grained and large crystals
INTERGROWN MINERAL CRYSTALS
• Extrusive: formed outside earth
– GLASSY TEXTURE appearance (obsidian)
– VESICULAR OR GAS POCKETS (pumice)
– fine grained and small crystals (basalt)
Sedimentary Rocks
• Sedimentary rock: generally formed from
compaction & cementation of smaller rocks and/or
sediments
• Generally formed in aquatic environments
• Key characteristics:
– VISIBLE SEDIMENTS, OTHER ROCKS,
CLASTS, OR SHELLS
(such as sand, pebbles, silt, and cobbles)
– FOSSILS MAY BE PRESENT
Metamorphic Rocks
• Metamorphic rock: formed when existing rocks
undergo intense heat and pressure
• Generally formed deep in lithosphere
• Key characteristics:
– FOLIATION: thin layering due to mineral alignment
– BANDING OR ZEBRA STRIPES: type of
foliation where minerals are separated into bands
If you see freckles or speckles it is….
Igneous…why
Intergrown Mineral Crystals
What type of rock is this??
Sedimentary…why
I see fossils
What type of rock is this??
Sedimentary…why
I see shells, fragments
Zebra Stripes…What type of rock is this??
Metamorphic…why
Banding or foliation
Holey Not Schist…What type of rock is this??
Igneous…why
Vesicular or gas pockets
What type of rock is this??
Sedimentary…why
I see rocks in this rock, fragments, or clasts
What type of rock is this??
Igneous…why
Glassy Texture
Elliptical Orbits and Eccentricity
• Ellipse: oval; elongated circle with two
centers called foci – the shape of all planetary
orbits in our solar system
• Eccentricity: degree of ovalness
Foci
Major Axis
Elliptical Orbits and Eccentricity
• Eccentricity = distance between foci
length of major
axis
distance between foci
length of major axis
Eccentricity is:
– Never less than zero or greater than 1
– Unitless
– Rounded to the nearest thousandths (0.000), so look at
the ten thousandths place 0.0000
YOU MUST MEASURE TO THE NEAREST
.1 OF A CENTIMETER!!
An ellipse
FOCI
Common error
MAJOR AXIS
Eccentricity
5.0
= --------------------------
Eccentricity
5.0
=
-------------------- =
9.2 cm
.5434= e=.543
Eccentricity
5.0
=
-------------------- =
9.2 cm
Compare the eccentricity of
the asteroid to the orbit of
Earth.
e=.543
Eccentricity
5.0 cm
= -------------------- =
9.2 cm
Compare the eccentricity of
the asteroid to the orbit of
Earth.
.543
Eccentricity
1. If this were the Earth’s orbit, where would the Sun be located?
2. Where would the Earth’s orbital velocity be the fastest?
SUN
Elliptical Orbits and Eccentricity
• Eccentricity = distance between foci
length of major
axis
For Example:
0.005
– 0.0049= rounds to _____________
For Example:
0.004
– 0.0042= rounds to _____________
For Example:
– 0.0049= rounds to
Common error
Elliptical Orbits and Eccentricity
Remember:
• The ellipse represents the shape of the path
a planet travels around the sun
• The sun is one of the two foci
• The greater the eccentricity, the more oval
the ellipse
Elliptical Orbits and Eccentricity
• The elliptical shape of an orbit causes the distance
from the sun to the planet to change
• When a planet is far from • When a planet is close to
the sun:
the sun:
– Gravitational attraction decreases
– Apparent diameter decreases
– Orbital velocity decreases
– Gravitational attraction increases
– Apparent diameter increases
– Orbital velocity increases
Finding the Epicenter of an
Earthquake
How do you find the epicenter of an earthquake?
1. Determine the arrival of the p-wave and
the s-wave.
Finding the Epicenter of an
Earthquake
2. Find the DIFFERENCE between the
arrival of the p-wave and the arrival of the
s-wave.
11:05 a.m.
-11:01 a.m.
4 minutes
WHAT DO YOU DO WITH THIS NUMBER?!?!?
Finding the Epicenter of
an Earthquake
• Difference between
the arrival times was 4
minutes
• MEASURE AND
MATCH!!
• The distance to the
epicenter is…
2600 km
Finding the Epicenter of an Earthquake
• What does the
circle
surrounding
Boise, Idaho
represent?
2,600 km
Finding the Epicenter of an
Earthquake
How many cities do you need in order to
find the epicenter of an earthquake
3!!!
-Why?
-Because you need the circles to
intersect and that can only happen with
3 cities.
Finding the Epicenter of an
Earthquake
Can you tell
where the
epicenter of
the
earthquake is
from this
information?
Finding the Epicenter of an
Earthquake
Where is the
epicenter of
this
earthquake?
Finding the Epicenter of an
Earthquake
OH NO!!!
What do you
do if this
happens?
Simply place
the X in the
middle of the
triangle
Earthquakes and Epicenters
• Epicenter: location on earth’s surface
directly above the focus (where the
earthquake originates)
• Distance to the epicenter can be determined
if the travel times of the P- and S-waves are
known
• Lagtime: difference in travel time between
the P- and S-waves
Earthquakes and Epicenters
Earthquakes and Epicenters
Lag time:
6 minutes
Earthquakes and Epicenters
Lag time:
6 minutes
Earthquakes and Epicenters
Lag time:
6 minutes
Earthquakes and Epicenters
Lag time:
6 minutes
4,400 km
Earthquakes and Epicenters
Earthquakes and Epicenters
• To locate the earthquake’s epicenter, a
minimum of three seismic stations are
needed
• With one station, there are many possible
epicenters
Station 1
Earthquakes and Epicenters
• With two stations, there are only two
possible epicenters
Station 2
Station 1
Earthquakes and Epicenters
• With three stations, there is only one
possible epicenters
Station 3
Station 2
Station 1
In Summary…
• Be prepared for test day
– Get supplies together the night before
– Get a good nights sleep and breakfast
• Start studying now
• If you don’t understand a topic, ask for help before
the test
• Practice test taking strategies
• During the exam: Take your time and read carefully
• Check your work if time is left
• Relax and take a deep breath!