Lab Practical Information Regents Earth Science When Thursday

Lab Practical Information Regents Earth Science

When? • Thursday – Everyone • All classes report to lab room either 240 or 239

Some Simple Rules • Be ON TIME • Do not be absent! • READ DIRECTIONS • There is to be absolutely NO TALKING – If you choose to talk, your exam booklet will be taken from you – You will receive a 0 for the Regents grade – You will have to re-take the Regents Exam in August & possibly have to go to Summer School

What is the Lab Practical? • First part of the Regents Exam • Test divided into 3 stations • Students are given 9 minutes per station

Station 1: Mineral and Rock Identification • Using a mineral identification kit, the student will determine the properties of • 1 Mineral – luster, breakage, hardness, streak • 2 Rocks will be classified as igneous, sedimentary, or metamorphic. Justification must also be given

Mineral Properties • Luster – metallic or nonmetallic—glassy, dull, pearly • Cleavage or Fracture – are the broken sides of the mineral semi-smooth surfaces, or non-smooth broken surfaces? • Streak – using white streak plate to see color of powdered mineral • Hardness – using glass scratch plate – hard scratches glass soft does not

Minerals: Luster- Metallic HEMATITE GALENA PYRITE Look for a reflective surface (similar to a mirror) Most minerals are nonmetallic

Minerals: Luster- Non-Metallic CALCIT E OLIVINE MICA SULFU R Look for earthy, dull, white, or non -reflective surfaces. Check the streak- if there is any streak at all, it will be colorless to white or yellow

Breakage • Fracture • Uneven breakage • Cleavage • Breaks along even surfaces

Hardness • Soft • Doesn’t scratch glass • Hard • Scratches glass

• • • Luster? Cleavage? Streak? Hardness? Mineral Name?

Identifying the Letter • On the practical, you will not need to give the name of the mineral. Instead, you will be giving the letter that the mineral has been assigned

Rock Properties and Classification • Classify 2 different rock samples – Sedimentary, Igneous, Metamorphic • State a reason for your classification

EXAMPLES • Rock Type: Sedimentary • Reason: Contains fossils • Rock Type: Metamorphic • Reason: Foliation

Igneous Rocks Basalt Pumice Granite Obsidian

Igneous Rocks Interconnected crystals in random order. THESE ARE NOT FRAGS OF OTHER ROCKS- THEY ARE MINERALS!!!! Course texture Glassy Texture Gas Pockets/Vesicular -> -> ->

Sedimentary Rocks Layered sediments Limestone Fossil

Sedimentary Rocks • Clastic/Fragmental Sand Particles Pebbles Within The Rock The diagram to the right Shows a close-up of Sandstone. You can see the individual Sand grains. You will have a magnifying Glass. USE IT!

Fossils (fossils are destroyed in metamorphic and igneous rocks) REMEMBER TO LOOK FOR SHELL FRAGMENTS- fossils may not be whole

Sedimentary Rocks: – Bedding or layering of sediments – Rounded grains, clasts, fragments or sediments – Fossils – Contain fragments of other rocks

Metamorphic Rocks Quartzite Gneiss Slate Schist

Metamorphic Rocks • Foliation

• Banding (Banding = GNEISS STRIPES!) • Mineral Alignment

• Non foliated crystals

Metamorphic Rocks: – Multiple-mineral composition – Interconnected mineral crystals WITH layering (foliation) – foliation - banding – Stretched pebbles – A high percent of mica minerals

Station 2: Locating an Epicenter • Find arrival times of p wave and s wave using seismograph • Find difference between p wave and s wave • Find distance • Draw two circles on the map and mark the epicenter

2: 33: 00 2: 35: 30 – 2: 33: 00 = 2: 35: 30 00: 02: 30

Earthquakes and Epicenters lag t ime 6 mi : n

Earthquakes and Epicenters Lag time: 6 minutes

Earthquakes and Epicenters Lag time: 6 minutes 4, 400 km

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

San Francisco 2, 600

Denver 2, 000 km

Wink 1, 100 km

Now place an X on the Epicenter

Station 3: Constructing and Analyzing an Asteriod’s Elliptical Orbit • Using two pins, a looped string, a metric ruler, and a calculator, the student will construct an ellipse, determine its eccentricity, and apply this information to our solar system.

Eccentricity A number indicating the roundness of an ellipse. Eccentricity = Distance Between Foci Length of Major Axis

Drawing an ellipse • First you will place your thumbtacks into the letters which are assigned to you. – They will be lined up FEDCBA ABCDEF

Drawing an ellipse • For example if you are given C as your foci you will place your thumbtack there. – They will be lined up FEDCBA ABCDEF

You can make an ellipse with 2 tacks and a string. The tacks are the “foci”, and if you put them further apart, the ellipse is more “eccentric” (one tack makes a circle).

Elliptical Orbits and Eccentricity • Eccentricity = 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)

Elliptical Orbits and Eccentricity • Eccentricity = distance between foci length of major axis distance between foci s length of major axis

Please Remember Measure to the nearest tenth! 0. 1 Calculate e to the nearest thousandth! 0. 001

Elliptical Orbits and Eccentricity • Eccentricity = distance between foci length of major axis distance between foci s length of major axis distance between foci = length of major axis 2. 0 cm = 0. 114 17. 5 cm

Please Remember Perfect circle Straight line e=0 e=1

The exam will give you the name of a planet. You are to look up the eccentricity of the orbit of this planet on the reference table and write this number in your lab- be sure to keep it three numbers after the decimal! Compare your eccentricity to the eccentricity of the planet If your number is closer to 0 than the planet, it is less elliptical than the planet If your number is closer to 1 than the planet, than your ellipse is more elliptical You will need to support your answer by saying your ellipse is either closer to zero or closer to one.

• • REMEMBER: Eccentricity of a circle = 0 (least eccentric) Eccentricity of a line = 1 (most eccentric) Remember: 0. 023 is closer to zero than 0. 123 because there is a number other than zero in the tenth’s place in the second number • ALSO: If the number on your calculator after you divide is 0. 0235, be sure to round up to 0. 024(5 or greater, round up) • If the number on your calculator is 0. 0234, then keep the third number the same: 0. 023 (less than 5, keep the number the same)

• Be sure to Read & Measure ACCURATELY • Remember: NO TALKING • Be on time! • Do not be absent!