Classical mechanics: how energy and forces affect the motion of macroscopic objects

Ex: As the driver inputs more energy into the car, the kinetic energy of the car increases proportionately

Chemical energy input into car (J)

Kin

etic

ene

rgy

(J)

Quantum mechanics: energy must be delivered to the electrons in specific quanta for them to be able to move to the next energy level

Energy delivered to electrons (J)

En

erg

y o

f ele

ctro

ns

(J)

1s

2s2p

3s

3d

3p

Heisenberg’s Uncertainty Principle: it is impossible to know precisely both the velocity (or energy) and the electron’s position at the same time.

Alice’s Adventures in Wonderland, Chapter VI:The Cheshire Cat Gets Weirder