Mistake Master
Mistake Master · AP Physics 2 · Unit 15 · Step-Through Animation
Only the Gap Leaves as Light
You'll learnthat a photon carries the difference between two levels and never one level's energy, that climbing swallows light while falling releases it, and that ionization is the jump to zero.
Hydrogen's bright lines are a subtraction problem: the levels belong to the atom, and only the gap between two of them ever leaves as light. Read a level instead and you predict a line nobody can see. Eleven short steps; press Next for each one.
the gap, not the level · up swallows and down releases · ionization goes to zero
Before you start
What you're looking at
Hydrogen's energy levels drawn to scale, and a strip of the visible band where the light that leaves the atom shows up as lines.
The question
What sets a photon's energy, which way the arrows run, and what ionization costs?
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