MC

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

At his Boy Scouts meetings, Ted was learning about rocks and minerals. His Scout leader told him that rocks are made of minerals. He decided to find out for himself. He took a rock and broke it into small pieces with a hammer. Then he compared the pieces of the rock with mineral samples that his teacher had at school by looking at them through a hand held microscope. He discovered that many of the pieces of rock were very similar to the mineral samples that he was comparing them to.

That evening at the supper table, his mother asked him if he liked the new casserole she had made for supper. He told her it was OK, but that it would be better if she put more cheese on the top next time she made it.

When he went to his room later that night, the light in his lamp would not go on. He decided to change the bulb to see if that was what was wrong. After he changed the bulb it still wouldnÕt light. So he followed the cord back to the plug and found out that it wasnÕt plugged in.

As Ted thought about his day, he realized that many people experiment to solve problems in their lives. Which of the following statements would sum up what Ted had learned that day?

Science is a way of knowing that is used by many people not just scientists.
The best way to learn about rocks is to ask your scout leader.
Learning to solve problems has nothing to do with science.
One has to be a scientist to solve problems.

Correct Answer: a

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

A rock has three minerals in it. One of them, quartz, has a hardness of 7. The second, feldspar, has a hardness of 4. The third, biotite, has a hardness of 2.5. What is true about the hardness of rock?

a. The hardness is 13.5, because that is the total hardness of the rock.

b. The hardness is 4.4, because that is the average of the hardness of the minerals in the

rock.

c. The hardness of the rock varies because each of the minerals has a different hardness.

d. The hardness is 2.5, because that is the hardness of the softest mineral.

Correct Answer: c

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

Minerals that break along smooth, flat surfaces have

a. cleavage

b. hardness

c. fracture

d. metallic luster

Correct Answer: a

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

A rock has large, inter-grown crystals in thin bands. Which type of rock would it be?

a. extrusive igneous

b. intrusive igneous

c. metamorphic

d. sedimentary

Correct Answer: c

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

What type of igneous rocks has individual mineral crystals that are generally too small to be seen without magnification?

a. chemical

b. clastic

c. extrusive

d. organic

Correct Answer: c

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

Which event would most likely produce igneous rocks?

a. deposition

b. earthquake

c. flood

d. volcano

Correct Answer: d

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

If you found an igneous rock with large crystals, what would the crystals tell you about how that rock was formed?

a. Cooled quickly above the surface.

b. Cooled quickly below the surface.

c. Cooled slowly above the surface.

d. Cooled slowly below the surface.

e. Cooled partially exposed.

Correct Answer: d

MC	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

What becomes trapped in pumice and scoria to form its holes?

a. foliation layers

b. mineral crystals

c. pockets of gas

d. sediments

Correct Answer: c

I	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

	Shiny	Air holes	Flat layers	Fossils	Particles stuck together	Glassy	Crystals
Metamorphic	X		X	X			X
Igneous	X	X			X	X	X
Sedimentary			X	X	X		X
Mineral	X					X	X

Sam made the above key while studying rocks in third grade. Use it to help decide what types of rocks are described below.

1. This rock has flat layers, fossils, and is shiny. According to SamÕs key it is:

a. metamorphic

b. igneous

c. sedimentary

d. mineral

2. This rock has particles stuck together, is glassy and is shiny. According to SamÕs key it is:

a. metamorphic

b. igneous

c. sedimentary

d. mineral

3. This rock has particles stuck together, has crystals, and has flat layers. According to SamÕs key it is:

a. metamorphic

b. igneous

c. sedimentary

d. mineral

Correct Answers:

1. a

2. b

3. c

I	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

Refer to the following diagram to answer the questions below.

1. If you found a rock with very large crystal grains, what type of rock would it be?

a. Gabbro

b. Granite

c. Obsidian

d. Pumice

e. Rhyolite

2. Rhyolite would contain crystals of what size?

a. larger to smaller

b. larger to non-existent

c. non-existent

d. smaller to non-existent

e. very large to larger

Correct Answers:

1. b

2. a

E	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

You are given two minerals that look exactly alike. One sample is gold. The other is pyrite. Describe at least two ways you could test the samples to tell the two minerals apart.

Ideal Answer: You could use the streak test to show the difference or determine the hardness of each. Gold is softer on Mohs scale and will leave a yellow streak, and pyrite leaves a brownish black streak. The hardness test would show that pyrite had the hardness of 6-6.5 and gold has the hardness of 2.5-3. Another test used to tell minerals apart is to determine the mineral's specific gravity, by measuring each mineral's density and comparing it to an equal volume of water. Pyrite has a specific gravity of approximately 5 and gold is 19.3.

Scoring Guide:

Streak test-40%

Hardness (or specific gravity)-40%

Spelling, punctuation, language usage-20%

E	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

The crust of the earth is approximately 8% aluminum (that's a lot). Why is it a good idea to recycle if there is no sign of running out of aluminum? Contrast the amount of energy required to recycle an aluminum can as compared to forming a new can from aluminum ore.

Possible Answer:

Recycling an aluminum can requires that it be melted, reformed, painted, and transported to the store. To make a new can from the raw materials requires the mining of aluminum ore. Machinery used in mining used a great deal of energy. The mined material must be transported to a processing plant where the aluminum is extracted. Transportation is by truck or train, again using a large amount of energy. Then the cans, must be manufactured, painted, and transported to the store. Eliminating the initial mining and refining save an enormous amount of energy.

Scoring Guide:

40% Explanation of recycling

40% Explanation of forming a new can from extraction of ore

20% Correct spelling, punctuation and language usage

E	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

Explain why minerals formed from cooled magma may have different crystal sizes.

Ideal Answer: The cooling rate of the magma determines the crystal size. If the magma cools quickly, small crystals will form. This will happen when magma reaches the surface and is exposed to water or air. If the magma stays trapped deep inside the earth, it will cool very slowly allowing time for large crystals to form.

Scoring Guide:

Small crystals from rapid cool-20%

Exposed to air or water-20%

Slow cooling, large crystals-20%

Deep inside earth-20%

Spelling, punctuation, language usage-20%

P	*8^th Grade Integrated Science*	*Standard:* 03
*Objective:* 01. Compare rocks and minerals and describe how they are related.
*ILO:*

Teacher Sheet

Materials Needed:

Assorted Rock Samples

Rock Identification charts for each student

Hand lens for each student

Procedures:

1. Hand out rock samples and hand lenses. Give students 10 to 15 minutes to observe and record characteristics.

2. Hand out identification charts, have students identify their rock and write the rock type on their paper.

3. Check to see who was able to correctly identify their rocks. Discuss problems as a class.

Scoring:

Logical list of 5 or more rock characteristics 5 points (1 point each)

Correct use of rock ID chart 5 points

To discover type of rock (i.e.: igneous, sedimentary, or metamorphic)

Give 1 point extra credit if students can find the proper name of the rock

Total 10 points possible