Download File - 8th Grade Earth Science

Name ______________________________ Class ___________________ Date __________________
Quick Lab
Water Planetesimals
MATERIALS
• medicine dropper
• water
• piece of wax paper
PROCEDURE
1. Use a medicine dropper to place two drops of water about 3 cm apart on a
piece of wax paper.
2. Lift one edge of the wax paper so that one drop of water moves toward the
other drop until the drops collide.
3. Add a third drop of water to the wax paper. Then, repeat step 2.
ANALYSIS
1. What happened when the water droplets collided?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
2. How does this activity model the formation of protoplanets?
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Earth Science
43
Planets of the Solar System
ANSWER KEY
Quick Lab
Water Planetesimals
Teacher’s Notes
Students could also use a straightened paper clip to draw the water droplets
together. You might point out that the force of attraction in this model is cohesion,
or the attractive force between particles of the same substance, while in the solar
nebula the attractive force is gravity.
SKILLS ACQUIRED
Constructing Models
Observing
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Earth Science
65
Planets of the Solar System
ANSWER KEY
Name ______________________________ Class ___________________ Date __________________
Quick Lab
Water Planetesimals
MATERIALS
• medicine dropper
• water
• piece of wax paper
PROCEDURE
1. Use a medicine dropper to place two drops of water about 3 cm apart on a
piece of wax paper.
2. Lift one edge of the wax paper so that one drop of water moves toward the
other drop until the drops collide.
3. Add a third drop of water to the wax paper. Then, repeat step 2.
ANALYSIS
1. What happened when the water droplets collided?
They merged to form larger droplets.____________________________________
_______________________________________________________________
_______________________________________________________________
2. How does this activity model the formation of protoplanets?
Answers may vary. Sample answer: Planetesimals grow by clumping together__
and attracting more matter. Collisions between planetesimals form larger______
bodies, just as the water droplets do._____________________________________
_______________________________________________________________
_______________________________________________________________
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Holt Earth Science
66
Planets of the Solar System