Idea 4of 7Builds onMass is the fuel
Join the light
Two tiny nuclei are rammed together. What comes out?
Today you'll discover
- what happens when two small nuclei are forced to touch
- why it takes the Sun's heat to make them
- the name for the process that powers every star
Think firstTwo tiny hydrogen nuclei are pushed together
Two tiny nuclei are rammed together hard enough to stick. What comes out?
Decide first, then press Next. Watch the two clusters resist, then merge, then weigh light.
Two tiny clusters of balls being pushed toward each other. After a prediction, they are shown repelling, then merged into one cluster with rays of energy leaving, then the ledger compares the mass before and after. The last step asks why fusion needs millions of degrees.
See the whole ideathe big idea and the key word, in one place
The big idea
Fusion: light nuclei join, and lost mass becomes energy.
Compare themFission: a heavy nucleus splits; a slow neutron starts it; reactors do it today. Fusion: light nuclei join; enormous heat starts it; stars do it, and we are still learning to.
Key word
- fusion
- the joining of light nuclei into a heavier nucleus, releasing energy; the process that powers stars
About this modelNuclei are drawn a million times too large relative to the atom, and the energy rays are a symbol, not a picture of light.
Nuclei are drawn a million times too large relative to the atom, and the energy rays are a symbol, not a picture of light.
Ready to use it?
- Tell fission from fusion by what starts each and what it does to the nucleus.