Elements and You
Summary:
Students are introduced to the periodic table and the concept of elements. The group will discuss how all material in the universe is composed of elements and that the atom is the smallest particle which still has the physical and chemical properties of any given element. As an exercise in statistics, the students will participate in a counting experiment, sampling the universal trail mix, to estimate the bulk composition of the universe. Finally, the idea of fusion is introduced with respect to creating heavier elements from hydrogen inside a star.
Purpose:
To introduce the idea of an element, the abundance of different elements in the universe and the role of fusion in a star.
Audience:
~ 20 students (grade range 6th-9th) in a group works well
Objectives:
- Understand what an element is
- Familiarize the students with a periodic table and common elements
- Determine the most abundant element in the universe
- Learn how heavier elements form from fusion
- Gain knowledge of the processes in the interior of a star
Materials:
- 1 lead brick for demonstration
- 1 plain pound cake for demonstration
- 1 knife to cut the pound cake
- napkins or paper plates for pound cake demonstration (1 per student)
- 1 large periodic table for display (if possible 1 small one per student)
- scoops or dixie cups for the trail mix demonstration (1 per student)
- 1 large mixing bowl
- 1 large bag of rice for the trail mix
- 1 small bag of unpopped popcorn kernels for the trail mix
- 1 small box of macaroni for the trail mix
- 1 small bag of uncooked beans for the trail mix (black beans worked well)
- 1 small bag of uncooked black-eyed peas for the trail mix
- 1 jar of multi-colored cake decorating sprinkle shapes
- 1 transparency of trail mix ingredients and what element they represent
- 16 lbs of red modeling clay (4 pounds per sphere = 32 sticks, to represent hydrogen)
- 8 lbs of yellow modeling clay (2 pounds per sphere = 16 sticks, to represent helium)
- 4 lbs of orange modeling clay (1 pound per sphere = 4 sticks, to represent carbon)
- 2 lbs of green modeling clay (1/2 pound per sphere = 2 sticks, to represent magnesium)
- 1 lb of blue modeling clay (1/4 pound per sphere = 1 stick, to represent iron)
- 1 transparency of model star clay colors and what element they represent
- 1 trash can or trash bag
Kit and Room Preparation:
- Universal Trail Mix: ~15 minutes
Mix the ingredients ahead of the planned activity in a large bowl
Use the same size "measuring cup" for preparation as the students will each have during the activity
- 40 scoops of rice (to represent 89% abundance of hydrogen in universe)
- 4 scoops of corn (to represent 9% abundance of helium)
- 2 scoops of macaroni (to represent 0.75% abundance of carbon)
- 2 scoops of beans (to represent 0.75% abundance of oxygen)
- 1 scoop of black-eyed peas (to represent 0.25% abundance of nitrogen)
- 1 scoop of sprinkles (to represent 0.25% abundance of all other elements)
- Clay star: ~ 2 hours to assemble
Make the clay star in 5 color coded layers
We found pre-cutting the ball as the layers were added to be helpful
- The interior clay ball will be blue in color ~ 2 inches in diameter
- The next layer will be green in color with a shell thickness of ~ 1 inch
- The next layer will be orange in color with a shell thickness of ~ 1 inch
- The next layer will be yellow in color with a shell thickness of ~ 2 inches
- The next layer will be red in color with a shell thickness of ~ 2-3 inches
Make extra fusion demonstration small clay balls
- 2 red ~ 1 inch in diameter for hydrogen
- 2 yellow ~ 1.5 inches in diameter for helium
- 1 orange ~ 2 inches in diameter for carbon
