Summary

In this activity, the students will explore the physical properties of different rocks. Students will have the opportunity to physically change the rocks, and make them part of a mixture in order to create finger paint.

Grade Level

Elementary School

Objectives

By the end of this activity, students should be able to

• Demonstrate safety practices during a class investigation.
• Describe physical properties of an object including size, shape, color, and texture.
• Complete a physical change.
• Create a mixture.
• Discover how rocks are useful in many ways.
• Communicate observations with others.

Chemistry Topics

This activity supports students’ understanding of

• Matter
• Physical properties
• Physical changes
• Mixtures

Time

Teacher Preparation: 15-20 minutes

Lesson: 1 hour

Materials

(Per student or pair of students)

• Red, yellow and blue colored rocks (you can substitute chalk)
• Small hammer or weight set to crush rocks or chalk
• 3 Thick Ziploc bags
• 5 pieces of white paper
• Mortars and muddlers
• 1 sorting tray or foam plate
• 1 glass of water
• Small transparent cups
• Pipettes/measuring spoons
• Optional:
  • Paint brushes
  • Rock set for classroom observation and description

Safety

• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.
• Students will be crushing and grinding small rocks or chalk, make sure to model how to crush to avoid any finger crushing during the activity.
• Small particles of dust will be obtained once the students grind their rocks or chalk, make sure to instruct not to smell it.

Teacher Notes

• This activity is best suited for kindergarten and first grade students.
• Making paint with students is a great activity for them to explore how paint is originally made from colored minerals that are naturally obtained from nature.
• Students can begin exploring rocks by making observations and describing their physical characteristics such as color, size, shape and texture.
• You can make an anchor chart or word list with your students about physical properties of the rocks to become familiar with the vocabulary.
• You can also make a list of how rocks are useful in our daily lives.
• You can pair students during this activity in order to help communicate observations.
• During this activity the students can explore how mixing primary colors can make secondary colors.
• Based on the age and ability of students you may or may not want to use the provided student handout.
• Activity procedure

1. Fold a small piece of paper into an envelope shape, and place the small rocks or chalk pieces to be crushed inside of it. This paper will help to contain all the small pieces inside.
   
   
   
   
2. Put the envelope containing the rocks or chalk inside of a plastic ziplock bag and start crushing it mix the hammer/weights or hands to obtain a powder. If you have mortars and muddlers, pour the dust in the mortar and grind it with the muddler to create a fine dust.
   
   
   
3. Pour the colored dust in the tray or foam plate and pour about 2 to 3 ml of water using the pipettes/measuring spoons in each compartment to make a soft paste.
   
   
   
4. Have fun mixing and painting with paintbrushes or fingers.