IB Physics E5 Definitions
This page contains our IB Physics definitions for E5. By learning each one of these definitions, you will fully cover the content for IB Physics 'Fusion & stars'.
Chandrasekhar Limit
The maximum mass of a white dwarf star (approximately 1.4 solar masses), beyond which it will collapse into a neutron star or black hole
Fission
It is the splitting of a large nucleus into two smaller nuclei, releasing energy
Fusion
It is the joining of two nuclei to form a larger nucleus, releasing energy
Hydrostatic Equilibrium
A balance between the outward radiation pressure from fusion reactions and the inward gravitational pull of the gases in a star
Jeans Criterion
A criterion determining when a cloud of gas will collapse to form a star, dependent on the mass, temperature, and density of the cloud
Radiation
It is the emission of electromagnetic waves from an atom by electrons
Supernova
A powerful explosion that occurs when a massive star exhausts its nuclear fuel and its core collapses
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