Overview and Background: Unit: Mock Rocks

Joyce Foley : Cheney USD 268

Science. : Mock Rocks : Science

Cheney : Grades 4 - 4 : Aug. - Jun.

Title:	Mock Rocks
Topics:	Earth Materials
Time Frame:	3 -5 days
Start Date:	-
Status:	Draft
Date Revised:

Other Designers:

Summary:
Students are introduced to earth materials through observations of a homemade mock rock. They use a nail to take the rock apart, and then put some of the rock material with water in a vial. After the mixture settles overnight, the top layer of liquid is transferred to an evaporating dish and observed for a few days. Students observe the crystals that formed and discuss the results of the rock ingredient separation.

Print Materials Needed:
Mock Rock Recipe

IMPORTANT: Make rocks 1 week before starting the lesson to allow them time to dry and harden.

Ingredients:
250 ml (1 cup) white flour
125 ml (1/2 cup) salt
10 ml (2 tsp) alum
125 ml (1/2 cup) water
5 drops red food coloring
5 drops blue food coloring
3 drops yellow food coloring
250 ml (1 cup) coarse sand
125 ml (1/2 cup) gravel - 2 different colors
30 ml (1/8 cup) oyster shell pieces

Equipment:
Bowl or large zip lock bag
Stirring spoon
Measuring utensils
Tray
Paper towels
Makes 18 * 5 cm mock rocks

To Make the Mock Rocks:

1. Mix the flour, salt, and alum together in the bowl or zip lock bag.

2. Measure the water and add food coloring to it.

3. Add the water to the flour mixture. Knead the mixture until it is uniform in color and texture and no longer sticks to the side of the bag or bowl. (Add a little more water if the dough is too crumbly.)

4. Add the sand and the gravel to the mixture and knead until it is well mixed.

5. Divide the mixture into 18 equal pieces about the size of a ping-pong ball. Place one of the rock balls into the palm of your hand, and with your thumb make a small hole in the center. Place 10-23 oyster shell pieces in the hole and mold the dough around them.

6. Work the ball of dough in your hands, smoothing its surface. Flatten the rock so that it is about 2 cm thick. (Thinner rocks will dry more quickly.)

7. Put the rocks on a tray lined with paper towels. Make sure the rocks do not touch each other. Place them in a warm area to dry. Turn them each day so they will dry thoroughly. It takes them about a week to dry, depending on the humidity. NOTE: Do not put rocks in microwave or oven. They will get too hard

8. Use the paper towel to clean the sand and gravel pieces from the utensils so that the solid materials do not go down the drain.

To Test the Mock Rocks:
Take one of the rocks apart 6 days after making them to be sure they are thoroughly dry and hard, but not so hard that they can't be broken in half by hand and taken apart with the nail (the geologist's pick).

Resources:
FOSS Earth Materials Module

Resource Attachments:	http://www.cheney268.com/4th/Foley/MockRocks.htm
Internet Resource Links:

Stage 1: Identify Desired Results

State:	KS
Title:	Science
Standard(s):	1:1.1 - Ask questions that they can answer by investigating. 1:1.2 - Plan and do a simple experiment. 2:1.2 - Classify objects by the materials from which they are made. 4:1.2 - Collect, observe, and become aware of properties of various soils. 4:1.4 - Describe the properties of many different kinds of rocks. 5:3.1 - Compare, contrast, and sort human-made versus natural objects.

Understandings:
user	The earth's crust is made from a limited number of elements combined in different ways to create different kinds of rocks.

Essential Questions:
User	How do rocks form? How do crystals form?

Knowledge and Skills:

K
Basic understanding of scientific method.

S
Writing a science lab report.

Stage 2: Determine Acceptable Evidence

Assessment Summary:
Students will create models of different types of rocks using cookie dough and other ingrediants and then explain how these rocks were formed in the earth's crust.

Task/Prompt: Chocolate Chip Rocks

Type: Performance Task

Topics: Earth Materials

Summary:
Students will create models of different types of rocks using cookie dough and other ingrediants and then explain how these rocks were formed in the earth's crust.

Print Materials Needed:

Resources:

Resource Attachments:

Internet Resource Links:
Link 1: http://
Link 2: http://
Link 3: http://
Link 4: http://
Link 5: http://

Notes:

Student Directions:
You are a geologist who is to create models for the Rock Museum. The museum will provide cookie dough. You will need to look for other ingredients that you can bring from home to create models that will demonstrate that rocks are made up of different elements. You will create four different models and explain what each model represents. Your oral presentation should be clear and accurate.

Other assessment evidence to be collected:

Stage 3: Plan Learning Experiences and Instruction

Learning Activities:

W
Show students some different kinds of rocks and have them brainstorm for how rocks were created.
Post essential questions.

H
Give each student a chocolate chip cookie. Have them break it and look at the different parts they see inside.

E
Mock Rock Activity (see Mock Rocks URL in Resources list)
Discuss how the students could find out about their rocks. Explain that geologists use special tools such as picks to take apart rocks to observe what the mock rocks are made of. Show them the nail, their geologist's pick.

Explain that the next challenge is to identify as many different parts of the rocks, or rock ingredients, as they can.

Each pair of students work with half of a rock on a paper plate.
Carefully separate the different ingredients and put into different containers. Make a list of ingredients which they think they can identify on a piece of paper.

Ask students to describe the leftover fine material, and how it could be separated further.

Each group needs a vial with lid and put in 25 ml of water. Put the lid on the vial, hold tightly, and shake.

Observe the contents and draw what is seen.

The next day, again draw what the contents of the vial look like after they have settled.

Carefully pour liquid from the vial into the dish - just enough to cover the bottom of the evaporating dish. The settled material can be tossed and the vial rinsed out.

Observe the dishes for several days until the liquid is gone.

Teams need to report their findings. (Small square crystals with X's in them.) Have them draw their findings.

When the water was added, the salt mixed with the water in a special way - it dissolved in the water. When the liquid from the vial was poured into the evaporating dish, the dissolved salt came out too. The water evaporated, and the salt crystals remained.

The students should find that the ingredients from this investigation were: gravel, sand, shells, flour, water, food coloring, alum, and salt.

R
Students should review the scientific method and see how this process helped them solve this problem.

E
Students will create models of different types of rocks using cookie dough and other ingrediants and then explain how these rocks were formed in the earth's crust.

Notes: