9
Production of the Elements
•H, He made in the big bang
•Elements up to Fe generated by fusion in stars
–expelled back into interstellar medium from red giants and supernova
•Elements heavier than Fe require energy to make:
neutron capture
–side effect in fusion chains
•s process
–in supernova explosions
•r process
–p+ capture occasionally important
•p process
From our text: Horizons, by Seeds