PURPOSE: Provides models for hydrogen burning to produce helium in stars via the proton-proton chain.
DESCRIPTION: Step 1:Two protons (medium size pink balls at the left) meet to form a deuteron (large blue ball), emitting a positron and a neutrino (two small orange balls). Step 2:The deuteron combines with a proton to form He3 (triplet of pink balls), emitting a photon (not shown in photograph). Step 3:Two He3 nuclei combine to form He4 (big blue ball) plus two protons (medium size pink balls). The process then repeats. Note that steps 1 and 2 must occur twice before step 3 can occur.
SUGGESTIONS: Indicate that the He4 (large blue ball) is actually composed of two protons and two neutrons.
REFERENCES: (PIRA unknown)
EQUIPMENT: Two medium-size pink balls connected together, one large blue ball, two separate small orange balls, three small pink balls connected together.
SETUP TIME: None.
Go back to Lecture-Demonstration Home Page.